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This study aimed to analyse the clinical and radiological outcomes after ulnar head replacement and to compare partial and total ulnar head implants. Twenty-two patients with 23 implants were available with a mean follow-up time of 7 years (range 1.3 to 17) after distal radioulnar joint arthroplasty. At the final follow-up, patients had a low level of pain at rest and during effort, a median Disabilities of the Arm, Shoulder, and Hand (DASH) score of 12 and Patient-Rated Wrist Evaluation score of 12 with partial ulnar head implants, and scores of 20 and 22 in total ulnar head implants, respectively. While the range of motion in patients with partial ulnar head implants was slightly reduced in comparison with the preoperative condition and to the patients with total ulnar head implants, there was a tendency to a higher grip strength and rotational torque. Both types of prosthesis showed sigmoid notch resorptions and resorptions around the neck. We conclude that the results after partial ulnar head replacement do not significantly differ from the total ulnar head implants in many aspects. Level of evidence: III

The present study aimed to develop a reliable dynamic measurement technique, which can be used directly in the outpatient setting, based on dorsal subluxation of the scaphoid on scaphoid shift test. This study was designed to evaluate feasibility and to quantify dorsal subluxation of the scaphoid in relation to the lunate. Based on a scaphoid shift test under ultrasonography, a standardized 3D test model was developed to measure subluxation. Sagittal subluxation ranged between 0 and 6 mm, as checked on the implemented scale. Four hand surgeons trained in ultrasonography (experience level II–V) performed blinded measurements (total of 52, n = 13 per investigator) with a standardized measurement protocol. Dorsal subluxation of the scaphoid was measured in relation to the lunate. Interobserver reliability on intraclass correlation coefficient (ICC) was excellent, at 0.97 (95% confidence interval, 0.930–0.992). Mean overall absolute measurement error was 0.27 mm ± 0.21. Dorsal subluxation of the scaphoid can thus be accurately measured on ultrasound with excellent interobserver reliability, quantifying and improving clinical assessment of scapholunate instability.

Background Intra-articular malunions of the finger can lead to deformity and loss of function and can be treated with intra-articular corrective osteotomies. The aim of this study was to evaluate radiographic joint congruency, feasibility and functional outcome of three-dimensional (3D) printed patient-specific instrumentation (PSI) for corrective osteotomies at the trapeziometacarpal and finger joints. Methods Computer-tomography (CT) scans were acquired preoperatively for standard 3D planning, which was followed by calculation of cutting planes and the design of individualized bone surface contact drilling, sawing and reposition guides. Follow-up CT scans and clinical examinations (range of motion, grip strength) were performed. Postoperative complications were documented and patient-reported outcome measurements were assessed (Single Assessment Numeric Evaluation (SANE) score, brief Michigan Hand Questionnaire (MHQ)). Results Ten patients (mean age 28.4 ± 12.8,range 13.8–51.3) years) were included with a mean follow-up of 21 ± 18 (3–59) months including seven osteotomies at the trapeziometacarpal or metacarpophalangeal joints and three at the proximal interphalangeal joint (PIP). All radiographic follow-up examinations showed the planned correction with good joint congruency and regular osseous consolidation. At the latest follow-up, the range of motion (ROM) increased and the average grip strength recovered to the level of the contralateral side. No postoperative complication was detected. The mean SANE score improved from 44 ± 23 (0–70) to 82 ± 12 (60–90) after a mean of 72 ± 20 (44–114) months. The mean postoperative brief MHQ was 92 ± 8 (71–98). Conclusion The use of 3D PSI in treating intra-articular malunions at the trapeziometacarpal and finger joints restored articular congruency accurately. ROM and grip strength improved postoperatively comparable to the healthy contralateral side and patient-reported outcome measures improved after medium-term follow-up.

The sequelae of high mechanical stress to the proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints of the fingers in elite sport climbers and its contribution to the development of osteoarthritis are still relatively unknown. The purpose of this study was to investigate the evolution of cartilage abnormalities of the PIP and DIP joints, as well as the progress of osteophytes, in the fingers of elite sport climbers with a minimum of 25 years of climbing history over the time period of the last 10 years. Moreover, their actual cartilage abnormalities and osteophyte occurrence were compared to non-climbing age-matched controls. Thirty-one elite male sport climbers and 15 male non-climbers underwent a sonographic examination of the PIP and DIP joint cartilage and osteophyte thickness in the frontal and sagittal plane of digits II-V of both hands. The same cohort had already been measured with an identical protocol 10 years earlier (follow-up rate of 100%). Compared to the baseline assessment 10 years earlier, the cartilage thickness of sport climbers has significantly decreased; however, it was still greater than in age-matched controls. Moreover, sport climbers showed significantly higher relative frequencies of osteophyte occurrence than non-climbers (all fingers and joints). Nevertheless, despite a substantial (and compared to baseline a further increased) occurrence of osteophytes in elite sport climbers, there was no association between the radiological signs of osteoarthritis and pain within the last six months prior the follow-up investigation.Highlights Long-term elite climbers show thicker cartilage and occurrence of Osteophytes in their fingers (especially Digit III) compared to controls already early in their career.Later occurrence of osteophytes increases (especially Digit II and IV) and cartilage decreases but is still thicker compared to controls. No association between those findings and pain was found.

Triple finger flexor tendon pulley injuries (A2-A3-A4) are generally reconstructed due to the considerable extent of bowstringing and resulting loss of range of motion (ROM). We present a series of 11 patients (12 cases) with triple pulley lesions. Six cases were diagnosed acutely (2 weeks after injury), one subacutely (4 weeks), 3 late (2 months) and 2 incidentally (asymptomatic). All patients but one were climbers. All acute and subacute patients were initially treated with two-pulley protection splint at the centre of the middle and proximal phalanx, proximal interphalangeal (PIP) joint extension splints for 2 months and had occupational therapy to prevent extension deficit. At 6 months' follow-up, the 6 patients with acutely and the 1 subacutely diagnosed injuries were back climbing at the same level. Almost no pain or restriction in daily activities remained; they had full flexion but a slight extension deficit (0-25°). Two of the three patients who were seen and diagnosed late had secondary pulley reconstruction because of persistent pain and increased extension deficit in the PIP joint. Both patients gained almost full range of motion without remaining pain. The third patient was asymptomatic with an extension deficit of 30°. Our case series suggests that early conservative treatment in acute and subacute triple pulley ruptures holds promise to decrease bowstringing, regain full flexion and return to pre-injury climbing level. Delayed diagnosis with delayed treatment is associated with less favorable results. Secondary pulley reconstruction of these chronic injuries yields good results even when performed months after the injury occurred.

The Sauvé–Kapandji procedure is an established treatment option for distal radioulnar joint dysfunction. We retrospectively analysed 36 patients following Sauvé–Kapandji procedure between 1997 and 2013. Fifteen patients were available for a follow-up after a mean of 13 years (range 6 to 23). Six patients needed revision surgery because of ulnar stump instability. Radiographs and sonography were performed to quantify the instability of the proximal ulnar stump. These showed a radioulnar convergence of 8 mm without weight and 2 mm while lifting 1 kg. Sonographically, the proximal ulnar stump dislocated by 8 mm to the volar side while applying pressure to the palm, compared with 4 mm on the contralateral side. Sonographically measured ulnar stump instability showed a positive strong correlation with the Disabilities of the Arm, Shoulder and Hand questionnaire and Patient-Reported Wrist Evaluations and a negative strong correlation with grip strength and supination torque. Because of the high incidence of revision surgery due to instability of the proximal ulnar stump, we restrict the use of the Sauvé–Kapandji procedure only to very selected cases. Level of evidence: IV

Background Intra-articular fractures are associated with posttraumatic arthritis if inappropriately treated. Exact reduction of the joint congruency is the main factor to avoid the development of arthrosis. Aim of this study was to evaluate feasibility of computer-assisted surgical planning and 3D-printed patient-specific instrumentation (PSI) for treatment of distal intraarticular radius fractures. Method 7 Patients who suffered a distal intraarticular radius fracture were enrolled in this prospective case series. Preoperative CT-scan was recorded, whereupon a 3D model was computed for surgical planning and design of PSI for surgical navigation. Postoperative accuracy and joint congruency were assessed. Patients were followed-up 3, 6 and 12 months postoperatively. Results Mean follow-up was 16 months. Over all range of motion was restored and flexion, extension and pronation showed significant recovery, p p p p p > 0.05 for fragments reduced with ligamentotaxis. Conclusion Computer-assisted and PSI navigated intraarticular radius fracture treatment is feasible, safe and accurate. The benefits of this method, however, do not outstand the additional effort. Level of evidence IV.

Our study described a computer-assisted, three-dimensional (3-D), planned surgical technique of a radial shortening osteotomy. The osteotomy of the distal radius was planned with computer assistance on 3-D bone models based on computed tomography data. The objective was to maximize the contact zone of the sigmoid notch with the ulnar head. Between 2012 and 2020 we treated 14 wrists in 11 patients with symptomatic ulnar-minus variance with a mean follow-up of 44 months (range 8 to 98) and a mean age of 28 years (range 19 to 38). Postoperatively, patients showed a decrease in pain at rest and during effort (numeric rating scale from 4.4 to 0 and 7.5 to 4.5, respectively). The range of motion postoperatively was similar to the contralateral side. Grip strength increased from 24 kg to 30 kg. The Disability of the Arm, Shoulder, and Hand and the Patient-Rated Wrist Evaluation scores were 28 and 35 postoperatively, respectively. Our technique of 3-D computer-assisted distal radioulnar joint reconstruction led to a pain reduction and improvement of the hand function in patients with symptomatic ulnar-minus variance. Level of evidence: IV

The aim was to analyse complications after surface replacing and silicone proximal interphalangeal (PIP) joint arthroplasty. All complications, reoperations (subsequent intervention without implant modification) and revisions (subsequent surgery with implant modification or removal) were extracted out of our registry for two cohorts: (1) Patients who received a surface replacing arthroplasty at the PIP joint using the CapFlex-PIP prosthesis and (2) patients who received a PIP silicone implant. Furthermore, radiographs were evaluated for deviations from the longitudinal finger axis. In our registry, 279 surface replacing implants and 424 silicone implants have been documented. The overall complication rate was 20% for surface replacements and 11% for silicone arthroplasties (p ≤ 0.01) with soft tissue-related events being the most prevalent in both groups. Reoperations were significantly more frequent after surface replacement (5.4%) than silicone arthroplasty (0.5%; p ≤ 0.001), while the revision rates did not differ significantly (4.4% and 3.3%, respectively; p = 0.542). Postoperative axis deviations were significantly less frequent in the surface replacement group (19% versus 58% for silicone arthroplasty; p ≤ 0.001). We recommend using a surface replacing implant in fingers with preoperative axis deviations and correctable anatomical situation, bearing in mind the higher risk of a second surgery. However, treatment outcomes also need to be considered before choosing one implant over another.

Purpose To evaluate the MRI anatomy of the scapho-trapezial-trapezoidal (STT) ligament complex in asymptomatic and symptomatic individuals. Material and methods In this retrospective study, STT ligament complex of 42 (male 69%, median age 37.5 years) asymptomatic (n = 25) and symptomatic (n = 17) (defined as pain described over the STT joint) individuals was examined using a high-resolution 3D proton density-weighted isovoxel sequence (MR arthrogram) with multiplanar reconstructions. Two musculoskeletal radiologists independently assessed visibility, signal intensity (SI), morphology, and thickness of the radiopalmar scapho-trapezial ligament (rpSTL), palmar scapho-capitate capsular ligament (pSCL), palmar STT capsule (pSTTC), and dorsal STT capsule (dSTTC). Results Interreader agreement ranged from fair to good and intraclass correlations were good. The rpSTL was almost always visible (85.7%/80.1%; reader 1/reader 2). The pSCL and dSTTC were visible in all cases. The pSTTC was visible in only 52.4%/42.9%. Mean thickness of the rpSTL, pSCL, pSTTC, and dSTTC was 1.4 ± 0.5 mm/1.3 ± 0.5 mm, 2.8 ± 0.7 mm/2.7 ± 0.6 mm, 0.5 ± 0.5 mm/0.4 ± 0.4 mm, and 0.5 ± 0.3 mm/0.3 ± 0.3 mm. Both readers rated SI of the rpSTL significantly more often as increased in the symptomatic group (increased SI in asymptomatic group: 20%/15%; symptomatic group: 56%/50%) (p-values p-values ranging between 0.188 and 0.890). For all other ligaments, no significant differences were observed regarding ligament visibility, morphology, and thickness (p-values ranging between 0.274 and 1.000). Conclusion The anatomy of the STT ligament complex can consistently be visualized on high-resolution 3D MRI. Increased signal intensity of rpSTL is significantly more frequent in patients with radial-sided wrist pain.

Background and Objectives: Three-dimensional planning and guided osteotomy utilizing patient-specific instrumentation (PSI) with the contralateral side used as a reference have been proven as effective in the treatment of malunions following complex fractures of the distal radius. However, this approach has not yet been described in relation to fracture reduction of the distal radius. The aim of this study was to assess the technical and logistical feasibility of computer-assisted surgery in a clinical setting using PSI for fracture reduction and fixation. Materials and Methods: Five patients with varied fracture patterns of the distal radius underwent operative treatment with using PSI. The first applied PSI guide allowed specific and accurate placement of Kirschner wires inside the multiple fragments, with subsequent concurrent reduction using a second guide. Results: Planning, printing of the guides, and operations were performed within 5.6 days on average (range of 1–10 days). All patients could be treated within a reasonable period of time, demonstrating good outcomes, and were able to return to work after a follow-up of three months. Mean wrist movements (°) were 58 (standard deviation (SD) 21) in flexion, 62 (SD 15) in extension, 73 (SD 4) in pronation and 74 (SD 10) in supination at a minimum follow-up of 6 months. Conclusions: Three-dimensional planned osteosynthesis using PSI for treatment of distal radius fractures is feasible and facilitates reduction of multiple fracture fragments. However, higher costs must be taken into consideration for this treatment.

Introduction Arthritis of the basal thumb is a relatively common condition also affecting younger patients. Wilson et al. described a 20°–30° closing wedge osteotomy of the first metacarpal bone to unload the trapeziometacarpal joint. It was the purpose of this study to analyze the clinical and radiographic outcome of patients who underwent proximal extension osteotomy of the first metacarpal bone using patient-specific planning and instruments (PSI). Methods All patients who underwent proximal metacarpal osteotomy for basal thumb arthritis at our tertiary referral center were retrospectively included. The patients underwent preoperative planning using computed tomography and 3D segmentation to build patient-specific guides and instruments for the operative treatment. Stable fixation of the osteotomy was achieved by internal plating. The inclusion criterion was a minimum follow-up of 1 year with clinical examination, including the Michigan Hand Outcomes Questionnaire (MHQ), and computed tomography to validate the correction. Complications and reinterventions were recorded. Results A total of eight Wilson osteotomies in six patients could be included at a mean follow-up duration of 33±16 months (range, 12 to 55 months). The patients were 49±8 years (range, 36 to 58 years) at the surgery and 88% were female. The postoperative MHQ for general hand function was 77±8 (range, 45 to 100) and the MHQ for satisfaction was 77±28 (range, 17 to 100). The working status was unchanged in 7/8 hands (6/7 patients). Radiographic analysis revealed successful correction in all cases with unchanged Eaton–Littler stage in 7/8 hands. No complications were recorded. Conclusion The combined extending and ulnar adducting osteotomy using patient-specific guides and instrumentation provides an accurate treatment for early-stage thumb arthritis. Level of evidence Type IV—retrospective, therapeutic study.

Background: Computer-assisted three-dimensional (3D) planning is increasingly delegated to biomedical engineers. So far, the described fracture reduction approaches rely strongly on the performance of the users. The goal of our study was to analyze the influence of the two different professional backgrounds (technical and medical) and skill levels regarding the reliability of the proposed planning method. Finally, a new fragment displacement measurement method was introduced due to the lack of consistent methods in the literature. Methods: 3D bone models of 20 distal radius fractures were presented to nine raters with different educational backgrounds (medical and technical) and various levels of experience in 3D operation planning (0 to 10 years) and clinical experience (1.5 to 24 years). Each rater was asked to perform the fracture reduction on 3D planning software. Results: No difference was demonstrated in reduction accuracy regarding rotational (p = 1.000) and translational (p = 0.263) misalignment of the fragments between biomedical engineers and senior orthopedic residents. However, a significantly more accurate planning was performed in these two groups compared with junior orthopedic residents with less clinical experience and no 3D planning experience (p < 0.05). Conclusion: Experience in 3D operation planning and clinical experience are relevant factors to plan an intra-articular fragment reduction of the distal radius. However, no difference was observed regarding the educational background (medical vs. technical) between biomedical engineers and senior orthopedic residents. Therefore, our results support the further development of computer-assisted surgery planning by biomedical engineers. Additionally, the introduced fragment displacement measure proves to be a feasible and reliable method. Level of Evidence: Diagnostic Level II © 2021, The Author(s)., Journal of Orthopaedic Surgery and Research, 16 (1), ISSN:1749-799X

Purpose To report and analyse factors affecting the outcome of streptococcal periprosthetic joint infections (PJIs). Methods A retrospective analysis of consecutive streptococcal PJIs was performed. Musculoskeletal Infection Society 2013 criteria were used. Outcome was compared with a prospective PJI cohort from the same institution. Results The most common isolated streptococcal species was Streptococcus dysgalactiae (9/22, 41%) among 22 patients included. Surgical treatment consisted of DAIR (debridement, antibiotics, irrigation and retention) in 12 (55%), one-stage revision arthroplasty in one (4%), two-stage revision arthroplasty in eight (37%) and implant removal in one (4%) patient. An infection free-outcome was achieved in 15 cases (68%), whilst seven (32%) patients failed initial revision and relapsed with the same pathogen, from which six were treated with DAIR and one with one-stage revision arthroplasty. No failures were observed in patients who received a two-stage revision. Failure rates did not differ in the cases treated with rifampin (1/5) from those without 6/17 (p = 0.55). There was no correlation between the length of antibiotic treatment and relapse (p = 0.723). In all failures, a persistent distant infection focus was identified at the time of relapse. Compared with our prospective PJI cohort, relapse rates were significantly higher 32% vs 12% (p Conclusion No correlation with the use of rifampin or length of antibiotic treatment was found. No failures were observed in patients who received a two-stage revision, which may be the surgical treatment of choice. A distant persisting infection focus could be the reason for PJI relapse with recurrent hematogenous seeding in the joint.

BACKGROUND Sport climbing induces physiological changes in the body of high-level climbers. In 2012, our study group demonstrated adaptions of elite climbers' soft tissues with thicker A2/A4-pulleys, flexor tendons and palmar plates compared to non-climbers. OBJECTIVES To assess these adaptations over time we examined all 31 (follow up 100%) climbers that participated in that baseline study again using ultrasonography after a follow-up of 10 years. MAIN FINDINGS (1) In climbers, a significant increase in A2 and A4-pulley and flexor tendon thickness over the last 10 years was observed (p 0.05); (2) at 10-years follow-up, all soft tissue thickness parameters (incl. palmar plates) were still significantly larger in climbers than in age-matched controls (p

Background Rock climbers are particularly susceptible to shoulder injuries due to repetitive upper-limb movements on vertical or overhanging terrain. However, the long-term effects of prolonged climbing on the shoulder joints are still unknown. Purpose The purpose of this study was to analyze the prevalence of pain and degenerative changes in the shoulder joints after high-level rock climbing over at least 25 years. We hypothesized that specific climber-associated patterns of degeneration would be found. Methods Thirty-one adult male high-level rock climbers were compared to an age- and sex-matched control group of 31 nonclimbers. All participants underwent a detailed interview, standardized clinical examination, and bilateral (climbers) or unilateral (nonclimbers, dominant side) magnetic resonance imaging (MRI) scans. Clinical and MRI findings of the groups were compared. Results The lifetime prevalence of shoulder pain in the rock climbers was 77%. The rock climbers had significantly more abnormalities in the labrum (82% vs. 52%; P = .002), long biceps tendon (53% vs. 23%; P = .006), and cartilage (28% vs. 3%; P = .005). These increased changes positively correlated with climbing intensity. There were no differences between the 2 groups with respect to rotator cuff tendon pathology (68% vs. 58%; P = .331) and acromioclavicular joint degeneration (88% vs. 90%; P = .713). Despite the increased degenerative changes in the rock climbers, their Constant score (CS) was still better than that of the nonclimbers (CS 94, interquartile range [IQR] 92-97, vs. CS 93, IQR 91-95; P = .019). Conclusions Prolonged high-level rock climbing leads to a high prevalence of shoulder pain and increased degenerative changes to the labrum, long biceps tendon, and cartilage. However, it is not related to any restriction in shoulder function.

Purpose To investigate the residual articular incongruity on computed tomography image data and the early clinical outcome of 3-dimensional planned and navigated intra-articular osteotomies of the distal radius. Methods We conducted a retrospective analysis of intra-articular osteotomies executed between 2008 and 2016. We identified 37 patients (aged 26–73 years) and performed a combined intra-articular and extra-articular osteotomy on 20 patients. A preoperative 3-dimensional plan with the superimposed bone of the contralateral healthy side was performed in each case to analyze and execute the osteotomy by intraoperative navigation. The residual articular incongruity was assessed by quantification of the maximal stepoff in the coronal or sagittal computed tomography scans. Clinical outcome, including range of motion, grip strength, and return to work, was assessed after a minimum follow-up of 12 months and compared with preoperative measurements. Results On average, the preoperative intra-articular stepoff was 2.5 mm (±0.6 mm; range, 1.4–4.2 mm) and was significantly reduced to 0.8 mm (±0.2 mm) after surgery. After surgery, 30 patients had a stepoff less than 1 mm; in 7, a stepoff of 1.1 to 1.4 mm was measured. After 1 year, 22 had no pain, 9 had slight pain during heavy work, and 5 had moderate pain with no improvement compared with their preoperative status, although wrist strength and range of motion improved in all 37 patients. One patient underwent a secondary radioscapholunate arthrodeses owing to persistent pain despite a congruent joint with a small residual intra-articular stepoff (0.6 mm). Conclusions Intra-articular osteotomies of the distal radius treated by 3-dimensional preoperative planning and patient-specific guides are an accurate technique to reduce articular incongruity to an average stepoff of 0.8 mm (range, 0.3–1.4 mm). The early clinical outcomes demonstrated overall reduction in pain and improvement of range of motion and grip strength in 36 of 37 patients. Type of study/level of evidence Therapeutic IV.

Fractures of the hamate are rare, and a clear treatment algorithm does not exist. Nonetheless, surgical treatment is generally recommended for displaced fractures using a dorsal approach. There is also a lack of data on hamate malunion. We present a case of a 28-year-old female with a coronal malunion of the hamate and hamate hook fracture. Because the triquetrum prevented direct access to the fracture, we planned and undertook a transtriquetral coronal osteotomy based on three-dimensional computed tomography imaging data. After removing the bone callus, reduction was possible with subsequent fixation. We recommend performing a transtriquetral osteotomy to treat an otherwise inaccessible fracture or malunion of select hamate fractures.

Malunions of the forearm and hand cause significant disability. Moreover, intraarticular deformities may contribute to early onset osteoarthritis. Such conditions require precise surgical correction in order to improve functional outcomes and prevent early or late complications. The purpose of this study was to describe the technical advantages of accurate anatomical reconstruction using 3D guided osteotomies and patient specific instruments (PSI) in multiple joints of the hand and forearm. Acquisition of three-dimensional (3D) datasets and surgical implementation of PSI was performed in a series of patients between December 2014 and July 2017. Patients had intra- or extra-articular malunions of the forearm, radiocarpal joint, trapeziometacarpal joint, or proximal interphalangeal joint. A previously described 3D surface model that incorporates CT data was used for segmentation (Mimics®, Materialise™, Belgium). For all the cases, CT scans of both forearms were acquired to use the contralateral uninjured side as the anatomic reconstruction template. Computer-assisted assessment of the deformity, the preoperative plan, and the design of PSI are described. Outcomes were determined by evaluating step-off correction, fusion, changes in range of motion (ROM) and grip strength. Six patients were included in the study; all achieved fusion. Improved clinical outcomes including pain reduction, better ROM and grip strength were obtained. Complete correction of intraarticular step-off was achieved in all cases with intraarticular malunions. 3D guided osteotomies are an established surgical treatment option for malunions of the hand and forearm. 3D analysis is a helpful diagnostic tool that provides detailed information about the underlying deformity. PSI can be developed and used for surgical correction with maximal accuracy for both intraarticular step-off and angular deformity.

Purpose Our study aimed to analyze the functional and radiological intermediate-term outcome of 3-dimensional-guided corrective osteotomies for malunited distal radius fractures and to evaluate the progression of osteoarthritis after this intervention. Methods All patients with malunited distal radius fractures who underwent 3-dimensional-guided corrective osteotomies from October 2008 to January 2015 were included. Pre- and postoperative range of motion, grip strength, and postoperative patient-reported outcomes were assessed. Pre- and postoperative osteoarthritis grading was performed using conventional radiographs and the osteoarthritis grading system described by Knirk and Jupiter. Additionally, the evaluation of articular stepoff was performed using pre- and postoperative computed tomography . Results Fifteen patients, with a mean follow-up of 6 years (range, 4.1–10.4 years), were included. According to rater 1, 8 cases had no postoperative osteoarthritis progression, 6 cases had progression of 1 grade, and 1 case had progression of 2 grades. According to rater 2, there was no progression in 11 cases, and there was progression of 1 grade in 2 cases and progression of 2 grades in 2 cases. Compared with before the surgery, the patients demonstrated a mean improvement of 14.8 kg (±12.6 kg) in grip strength after the surgery. At the last follow-up, the mean Patient-Rated Wrist Evaluation score was 11.8 (±12.0), the mean Disabilities of the Arm, Shoulder and Hand score was 11.1 (±11.4), and the mean residual pain score on the visual analog scale was 0.8 (±1.0). Conclusions The intermediate-term outcome of 3-dimensional-guided corrective osteotomies for distal radius intra-articular malunions showed excellent patient-reported outcomes and no clinically relevant progression of osteoarthritis. Type of study/level of evidence Therapeutic IV.

Neglected or incorrect treatment of pediatric radial neck fractures may lead to symptomatic malunions. Computer-assisted corrective osteotomies with patient-specific guides have been proposed as a promising technique for the reconstruction of malunited long bone deformities. The aim of this study was to evaluate the accuracy and clinical outcome of this technique in children with malunited fractures of the radial neck. Four children [2 boys, 2 girls; mean age 12 (10-16) years] underwent computer-assisted closing wedge osteotomy of the radial neck. The contralateral uninjured side was used as a reconstruction template. Computed tomography were performed 8 weeks postoperatively to confirm bony consolidation and to quantify residual 3D rotational and translational displacement error. Clinical outcome [pain, range of motion (ROM)] and overall satisfaction were documented. Preoperative subluxation of the radial head could be corrected in 2 of 3 patients. One patient had to be revised because of secondary traumatic loss of reduction. At the last follow-up [mean 16 (range, 12-24) months], all patients were pain free for activities of daily living (preoperative pain: visual analog scale 6). Pain during sport activities could be substantially reduced (visual analog scale 8→2). Although the procedure failed to improve ROM, none of the patients had limitations regarding work, daily, or sports activities. Yet, restricted ROM was considered as a cosmetic problem in 1 patient. Full consolidation of the osteotomy site, with no signs of avascular necrosis of the radial head, was achieved in all patients. The deformity could be substantially reduced, from a 3D angle of 13-40 degrees to 3-7 degrees (58%-89% deformity correction). Computer-assisted corrective osteotomy is a novel technique for the treatment of radial neck malunions that led to adequate pain reduction and 3D accuracy of deformity correction in our small case series. Despite the lack of improved ROM, all patients were satisfied and would undergo the same procedure again.

Background The surgical treatment of malunions after midshaft clavicle fractures is associated with a number of potential complications and the surgical procedure is challenging. However, with appropriate and meticulous preoperative surgical planning, the surgical correction yields satisfactory results. The purpose of this study was to provide a guideline and detailed overview for the computer-assisted planning and 3-dimensional (3D) correction of malunions of the clavicle. Methods The 3D bone surface models of the pathologic and contralateral sides were created on the basis of computed tomography data. The computer-assisted assessment of the deformity, the preoperative plan, and the design of patient-specific guides enabling compression plating are described. Results We demonstrate the benefit and versatility of computer-assisted planning for corrective osteotomies of malunions of the midshaft clavicle. In combination with patient-specific guides and compression plating technique, the correction can be performed in a more standardized fashion. We describe the determination of the contact-optimized osteotomy plane. An osteotomy along this plane facilitates the correction and enlarges the contact between the fragments at once. We further developed a technique of a stepped osteotomy that is based on the calculation of the contact-optimized osteotomy plane. The stepped osteotomy enables the length to be restored without the need of structural bone graft. The application of the stepped osteotomy is presented for malunions of the clavicle with shortening and excessive callus formation. Conclusions The 3D preoperative planning and patient-specific guides for corrective osteotomies of the clavicle may help reduce the number of potential complications and yield results that are more predictable.

Purpose Accuracy and feasibility of corrective osteotomies using 3-dimensional planning tools and patient-specific instrumentation has been reported by multiple authors with promising results. However, studies describing clinical outcomes following these procedures are rare. Therefore, the purpose of this study was to compare the results of computer-assisted corrective osteotomies of the diaphyseal and distal radius with a conventional non–computer-assisted technique regarding duration of surgery, consolidation of the osteotomy, and complications. Also, subjective and objective clinical outcome parameters were assessed. Methods We retrospectively compared the results of 31 patients who underwent a corrective osteotomy performed conventionally with 25 patients treated with a computer-assisted method (CA) using patient-specific instrumentation. Baseline data were similar among both groups. The duration of surgery, bony consolidation, complications, gain in range of motion, and subjective outcome were recorded. Results The mean operating time was significantly shorter in the CA group compared with the conventional group. After 12 weeks, significantly more osteotomies were considered healed in the CA group compared with the conventional group. Two patients in the CA group required revision surgery to treat nonunion of the osteotomy. Otherwise clinical results were similar among both groups. Conclusions The results demonstrate that the computer-assisted method facilitates shorter operation times while providing similar clinical results. Type of study/level of evidence Therapeutic IV.

The impact of extensive loads on the cartilage of the proximal interphalangeal- (PIP) and distal interphalangeal (DIP) joints of the fingers in elite sport climbers are relatively unknown. The purpose of this study was to investigate the changes in the cartilage of the PIP and DIP joints as well as the existence of osteophytes, in fingers of elite sport climbers with a minimum of 15 years of climbing history. Thirty-one elite male sport climbers and 20 male non-climbers volunteered for the current cross-sectional observation. By means of ultrasonography, the thickness of cartilage of the PIP and DIP joints in a sagittal and frontal plane of the digits II to V of both hands, as well as the existence of osteophytes on the dorsal aspect of the phalanges were assessed. The main results were: (1) cartilage thickness revealed to be significantly greater in climbers than non-climbers,; (2) larger cartilage thickness differences were found at the DIP joints; (3) while climbers showed a substantial occurrence of osteophytes with highest relative frequencies at Dig III, in the group of non-climbers no osteophytes were observed; (4) small to moderate correlations were found between the cartilage and osteophyte thickness of climbers at the PIP and DIP joints and Dig III. In conclusion, an accumulation of repetitive climbing-related stress to the fingers of elite sport climbers over the career may induce degenerative changes at the PIP and DIP joints.

Background Preoperative three-dimensional planning and intraoperative navigation by patient-specific instruments is a promising method for the exact correction of bone deformities. Nevertheless, disadvantages of current concepts are the missing options of adapting the surgical plan intraoperatively. By providing the surgeons with a controlled length adjustment through the patient-specific instruments, the application area can usefully be expanded in the treatment of clavicle osteosyntheses. Methods In three cases, preoperative three-dimensional surgical planning with the intraoperative use of patient-specific instruments was applied. The computer-assisted assessments of clavicle deformities, the preoperative plan, and the design of patient-specific instruments were created on the basis of computed tomography data. Reduction guides for restoring length and rotation according to the mirrored healthy contralateral side were enhanced with adaptable length adjustment functions. The screw thread of the reduction guides enabled temporary distraction of the clavicle fracture fragments and a controlled compression of the optionally used interposed bone block between clavicle fragments. Results Navigated clavicle osteosyntheses by enhanced patient-specific instruments was executed uneventful in all three cases. The surgeon was able to adapt clavicle length in a planned axis intraoperatively as clinically desired. Conclusion Computer-assisted planning of clavicle osteosynthesis and surgical navigation with additional adaptable patient-specific instruments can usefully expand the previous application areas. By using guided length adjustments, the fragments and optionally the graft can be compressed along a planned axis as desired to ensure optimal bone healing. Level of evidence Basic science study, Surgical technique Electronic supplementary material The online version of this article (10.1186/s13018-019-1151-8) contains supplementary material, which is available to authorized users.

3D computer-assisted corrective osteotomy has become the state-of-the-art for surgical treatment of complex bone deformities. Despite available technologies, the automatic generation of clinically acceptable, ready-to-use preoperative planning solutions is currently not possible for such pathologies. Multiple contradicting and mutually dependent objectives have to be considered, as well as clinical and technical constraints, generally requiring iterative manual adjustments. This leads to unnecessary efforts and unbearable clinical costs, hindering also the quality of patient treatment. In this paper, we propose an optimization framework for the generation of ready-to-use preoperative planning solutions in a fully automatic fashion. An automatic diagnostic assessment using patient-specific 3D models is performed for 3D malunion quantification and definition of the optimization parameters. Afterward, clinical objectives are translated into the optimization module, and controlled through tailored fitness functions based on a weighted and multi-staged optimization approach. The optimization is based on a genetic algorithm capable of solving multi-objective optimization problems with non-linear constraints. The framework outputs a complete preoperative planning solution including position and orientation of the osteotomy plane, transformation to achieve the bone reduction, and position and orientation of the fixation plate and screws. A qualitative validation was performed on 36 consecutive cases of radius osteotomy where solutions generated by the optimization algorithm (OA) were compared against the gold standard (GS) solutions generated by experienced surgeons. Solutions were blinded and presented to 6 readers, who voted OA solutions to be better in 55% of the time. The quantitative evaluation was based on different error measurements, showing average improvements with respect to the GS., Comment: 37 pages, 15 figures, submitted to Medical Image Analysis Journal

Objective Hamate hook fractures are rare injuries, comprising 2% to 4% of all carpal fractures. Climbing athletes seem to be affected more frequently than others, as they strain the passive and active anatomical structures of their hands and fingers to maximum capacity during training or competing. This stress is transmitted to the hook of the hamate by tightened flexor tendons, which creates high contact pressure to the ulnar margin of the carpal tunnel. Injuries of the hamate hook, caused by contact pressure of the anatomical structures, are rare and occur nearly exclusively during climbing. Methods We diagnosed 12 athletes with hamate hook fractures who presented with diffuse pain in the wrist joint, which occurred either during or after climbing. Radiographs or computed tomography revealed fractures in the hamate bones in most of the patients; therapy consisted of consequent stress reduction. Results Follow-up investigations found that all athletes were free of symptoms after 10.7 ± 5.1 (6–24) (mean ± standard deviation with range) weeks. Resection of the hamate hook was necessary in 3 patients. All patients regained their preinjury climbing level. Conclusion Climbers with an unspecific, diffuse pain in the wrist need to be examined by radiograph and , if radiograph is unclear , computed tomography or magnetic resonance imaging to detect or exclude the diagnosis of hamate fracture in order to avoid severe complications.

Background: Surgical planning of corrective osteotomies is traditionally based on conventional radiographs and clinical findings. In the past 10 years, 3-dimensional (3D) preoperative planning approaches with patient-specific guides have been developed. However, the application of this technology to posttraumatic deformities of the metacarpals and phalangeal bones has not yet been investigated. Our goal was to evaluate the feasibility of the surgical application to the latter and to evaluate the extent and precision of correction. Methods: We present results of 6 patients (8 osteotomies) treated with phalangeal or metacarpal corrective osteotomy. Deformities were located in the third ray in 1, fourth ray in 3, and fifth ray in 4 cases. Six malunited metacarpal bones (1 intra-articular) and 2 deformed proximal phalanges were treated. Computer-based 3D preoperative planning using the contralateral hand as a template allowed the production of 3D-printed patient-specific guides that were used intraoperatively for navigation. The precision of the reduction was assessed using pre- and postoperative computed tomography by comparing the postoperative bone model with the preoperatively simulated osteotomy. Range of motion and grip strength were documented pre- and postoperatively. Results: The mean follow-up time was 6 months (range: 5-11 months). Rotational deformity was reduced from a mean of 10.0° (range: 7.2°-19.3°) preoperatively to 2.3° (range: 0.7°-3.7°) postoperatively, and translational incongruency decreased from a mean of 1.4 mm (range: 0.7-2.8 mm) to 0.4 mm (range: 0.1-0.9 mm). Conclusion: Preliminary results indicate that a precise reduction for corrective osteotomies of metacarpal and phalangeal bones can be achieved by using 3D planning and patient-specific guides.

The incidence of lumbrical muscle tear is increasing due to the popularity of climbing sport. We reviewed data from 60 consecutive patients with a positive lumbrical stress test, including clinical examination, ultrasound and clinical outcomes in all patients, and magnetic resonance imaging in 12 patients. Fifty-seven patients were climbers. Lumbrical muscle tears were graded according to the severity of clinical and imaging findings as Grade I–III injuries. Eighteen patients had Grade I injuries (microtrauma), 32 had Grade II injuries (muscle fibre disruption) and 10 had Grade III injuries (musculotendinous disruption). The treatment consisted of adapted functional therapy. All patients completely recovered and were able to return to climbing. The healing period in Grade III injuries was significantly longer than in the patients with Grade I or II injuries ( p Level of evidence: IV

Among the various reasons for chronic posttraumatic ulnar-sided wrist pain, instability of the distal radioulnar joint (DRUJ) has recently received major attention and finally achieved fundamental progress in understanding thanks to anatomic and biomechanical studies. This has resulted in more physiological and successful treatment methods compared with the historic options. One and the most dramatic surgical technique consists in the replacement of the main ligamentous stabilizer of the DRUJ, the so-called triangular fibrocartilage, with a tendon graft. On the basis of our experience, the refined surgical technique is presented as well as the results obtained in a retrospective consecutive case series of 48 patients with 48 wrists followed-up for 16 months in average (6 to 43) clinically and radiographically. Out of 48 unstable DRUJ's stability was restored in 44 patients associated with a significant pain relief by 1.44 points (on a scale 0 to 4). There was however a loss of forearm rotation of 20 degrees in average (pronation-8 degrees; supination-12 degrees), whereas the range of motion of the wrist and grip strength remained unchanged. We did not find any influence on the result by performing simultaneous ulnar shortening osteotomy, the duration of cast immobilization or the positioning in the cast. There were no postoperative complications, 4 failed cases needed secondary procedures (2× rereconstruction, 2× Sauve-Kapandji-operation).

Corrective osteotomies of the forearm based on 3D computer simulation using contralateral anatomy as a reconstruction template is an approved method. Limitations are existing considerable differences between left and right forearms, and that a healthy contralateral anatomy is required. We evaluated if a computer model, not relying on the contralateral anatomy, may replace the current method by predicting the pre-traumatic healthy shape. A statistical shape model (SSM) was generated from a set of 59 CT scans of healthy forearms, encoding the normal anatomical variations. Three different configurations were simulated to predict the pre-traumatic shape with the SSM (cross-validation). In the first two, only the distal or proximal 50% of the radius were considered as pathological. In a third configuration, the entire radius was assumed to be pathological, only the ulna being intact. Corresponding experiments were performed with the ulna. Accuracy of the prediction was assessed by comparing the predicted bone with the healthy model. For the radius, mean rotation accuracy of the prediction between 2.9 ± 2.2° and 4.0 ± 3.1° in pronation/supination, 0.4 ± 0.3° and 0.6 ± 0.5° in flexion/extension, between 0.5 ± 0.3° and 0.5 ± 0.4° in radial-/ulnarduction. Mean translation accuracy along the same axes between 0.8 ± 0.7 and 1.0 ± 0.8 mm, 0.5 ± 0.4 and 0.6 ± 0.4 mm, 0.6 ± 0.4 and 0.6 ± 0.5 mm, respectively. For the ulna, mean rotation accuracy between 2.4 ± 1.9° and 4.7 ± 3.8° in pronation/supination, 0.3 ± 0.3° and 0.8 ± 0.6° in flexion/extension, 0.3 ± 0.2° and 0.7 ± 0.6° in radial-/ulnarduction. Mean translation accuracy between 0.6 ± 0.4 mm and 1.3 ± 0.9 mm, 0.4 ± 0.4 mm and 0.7 ± 0.5 mm, 0.5 ± 0.4 mm and 0.8 ± 0.6 mm, respectively. This technique provided high accuracy, and may replace the current method, if validated in clinical studies. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2630-2636, 2017.

Background Corrective osteotomies of malunited fractures of the proximal and distal humerus are among the most demanding orthopedic procedures. Whereas the restoration of the normal humeral anatomy is the ultimate goal, the quantification of the deformity as well as the transfer of the preoperative plan is challenging. The purpose of this study was to provide a guideline for 3-dimensional (3D) corrective osteotomies of malunited intra-articular fractures of the humerus and a detailed overview of existing and novel instruments to enlarge the toolkit for 3D preoperative planning and intraoperative realization using patient-specific guides. Methods We describe the preoperative 3D deformity analysis, relevant considerations for the preoperative plan, design of the patient-specific guides, and surgical technique of corrective osteotomies of the humerus. Results The presented technique demonstrates the benefit of computer-assisted surgery for complex osteotomies of the humerus from a preoperative deformity analysis to the creation of feasible surgical procedures and the generation of patient-specific guides. Conclusions A 3D analysis of a post-traumatic deformity of the humerus, 3D preoperative planning, and use of patient-specific guides facilitate corrective osteotomies of complex malunited humeral fractures.

Objective To evaluate the effectiveness of conservative treatment of finger flexor tendon pulley rupture with a pulley-protection splint (PPS) with regard to reduction in tendon-phalanx distance (TPD) and functional and sport-specific outcomes in a retrospective case series. Methods Tendon-phalanx distance in active forced flexion was measured before and after treatment in ultrasound records. Functional and sport-specific outcomes were evaluated by means of a questionnaire, which also contained instructions for self-measurement of finger range of motion and finger strength. Results Forty-seven complete pulley ruptures in 45 rock climbers (mean age, 33.4 years; range, 21.8–56.2 years) were included in the study. In the 39 patients who had follow-up ultrasound examination, PPS treatment decreased mean ± SD TPD from 4.4 ± 1.0 mm to 2.3 ± 0.6 mm after A2 pulley rupture and from 2.9 ± 0.7 mm to 2.1 ± 0.5 mm after A4 pulley rupture. Tendon-phalanx distance was reduced in all patients. Finger range of motion (n = 42) and finger strength (n = 22) did not differ significantly between treated and contralateral sides. Of the 43 climbers who completed questionnaires, 38 had regained their previous climbing level a mean 8.8 months after pulley rupture; 1 reported reduced finger dexterity; 39 assessed their treatment results to be good, and 4 to be very good. Conclusions The PPS is an effective conservative treatment modality for pulley ruptures, which reduces TPD and enables the patient to regain previous finger function.

Purpose To virtually assess nonunions of the scaphoid waist using 3-dimensional computed tomography (CT) reconstruction for the amount of displacement of the distal fragment and the postfracture reduction position using the intact opposite scaphoid for reference. Methods We generated 3-dimensional reconstructions for 11 nonunions of the scaphoid waist and the contralateral intact scaphoids based on CT. The mean age of the patients was 25 years and the time from injury to the CT scan was 2.4 years. We used the mirrored 3-dimensional model of the healthy scaphoid to guide virtual reduction of the nonunion and calculated the amount of displacement of the distal pole fragment from prereduction to postreduction. We compared the results with the intrascaphoid angles calculated using single CT slices. Results The scaphoid nonunions showed a mean flexion deformity of 23°, an ulnar deviation of 5°, and a pronation deformity of 10°. Mean translation was 0.9 mm volarward, 0.2 mm radialward, and 3.3 mm distalward. After reduction, all scaphoids showed a bony overlap on the dorsoradial side; the mean volume of this region was 3% of total bone volume. There was no correlation between the degree of displacement and the intrascaphoid angle measurements. Conclusions Preoperative planning for scaphoid reconstruction is usually performed using conventional radiographs and single CT slices. However, by synthesizing the information from the CT into a 3-dimensional reconstruction, an exact analysis is possible. This method also allows quantification of prosupination displacement. The postreduction area of dorsal bone overlap may be due to appositional callus formation. Clinical relevance Simple volar opening of the scaphoid allows correction of angulation deformities but results in lengthening of the scaphoid. Correct reduction of the scaphoid fragments is often only possible if the dorsal appositional callus is resected.

Purpose To study the configuration of the proximal interphalangeal joint volar plate (VP) in the crimp grip position (metacarpophalangeal joint at 0° to 45° flexion, proximal interphalangeal joint at 90° to 100° flexion, and distal interphalangeal joint at 0° to 10° hyperextension) using magnetic resonance imaging techniques in healthy volunteers and cadaver fingers and to compare the results with histological sections. Methods Magnetic resonance imaging was performed on 24 fingers of 8 healthy volunteers and 12 fingers of 4 embalmed cadaver hands in the neutral position and in the crimp grip position. The translation of the VP body relative to the middle phalanx base during finger flexion was measured. In 6 of 12 cadaver specimens, a load of 10 N was applied to the flexor tendons to examine how this would affect the histological VP fiber configuration. Results When the flexor tendons were under load in the crimp grip position, the volunteers' VP body was translated an average of 3.2 mm, and the cadaver fingers' VP body was translated an average of 3.0 mm, relative to the middle phalanx base in a distal direction. Histological analysis of the crimp grip position revealed reversing fibers in the VP insertion at the base of the middle phalanx when the flexor tendons were under load and the VP body was translated. When no load was applied in the crimp grip position, no translation of the VP body occurred. Conclusions This article describes a VP translation in a distal direction relative to the middle phalanx base in the crimp grip position when the flexor tendons are under load. Clinical relevance A more precise knowledge of the histological properties of the proximal interphalangeal joint VP during finger flexion can be expected to provide greater diagnostic capabilities and can lead to a better comprehension of injuries.

A number of strategies and protocols for the expression, purification and kinetic characterization of human caspases are described in the literature. We have systematically revised these protocols and present comprehensive optimized expression and purification protocols for caspase-1 to -9 as well as improved assay conditions for their reproducible kinetic characterization. Our studies on active site titration revealed that the reproducibility is strongly affected by the presence of DTT in the assay buffer. Furthermore, we observed that not all caspases show a linear relationship between enzymatic activity and protein concentration, which explains the discrepancy between published values of specific activities from different laboratories. Our broad kinetic analysis allows the conclusion that the dependency of caspase activities on protein concentration is an effect of concentration-dependent dimerization, which can also be influenced by kosmotropic salts. The protocol recommendations as an outcome of this work will yield higher reproducibility regarding expression and purification of human caspases and contribute to standardization of enzyme kinetic data.

Opening-wedge osteotomies of the distal radius, performed with three-dimensional printed patient-specific instruments, are a promising technique for accurate correction of malunions. Nevertheless, reports of residual malalignments and discrepancies in the plate and screw position from the planned fixation exist. Consequently, we developed a patient-specific ramp-guide technique, combining navigation of plate positioning, osteotomy cutting, and reduction. The aim of this study is to compare the accuracy of navigation of three-dimensional planned opening-wedge osteotomies, using a ramp-guide, over state-of-the-art guide techniques relying solely on pre-drilled holes.A retrospective analysis was carried out on opening-wedge osteotomies of the distal radius, performed between May 2016 and April 2017, with patient-specific instruments. Eight patients were identified in which a ramp-guide for the distal plate fixation was used. We compared the reduction accuracy with a control group of seven patients, where the reduction was performed with pre-drilled screw holes placed with the patient-specific instruments. The navigation accuracy was assessed by comparing the preoperative plans with the postoperative segmented, computed tomography scans. The accuracy was expressed using a 3D angle and in measurements of all six degrees of freedom (3 translations, 3 rotations), with respect to an anatomical coordinate system.The duration of the surgery of the ramp-guide group was significantly shorter compared to the control group. Significantly less rotational and translational residual malalignment error was observed in the open-wedged osteotomies, where patient-specific instruments with ramp-guides were used. On average, a residual rotational malalignment error of 2.0° (± 2.2°) and a translational malalignment error of 0.6 mm (± 0.2 mm) was observed in the ramp-guide group, as compared to the 4.2° (± 15.0°) and 1.0 mm (± 0.4 mm) error in the control group. The used plate was not significantly positioned more accurately, but significantly fewer screws (15.6%) were misaligned in the distal fragment compared to the control group (51.9%).The use of the presented ramp-guide technique in opening-wedge osteotomies is improving reduction accuracy, screw position, and surgical duration, compared to the existing patient-specific instrument based navigation methods.

In this study the influence of the grip position (crimp grip vs. slope grip position) on the pulley system of the finger was investigated. For this purpose 21 cadaver finger (11 hands, 10 donors) were fixed into an isokinetic loading device. Nine fingers were loaded in the slope grip position and 12 fingers in the crimp grip position. The forces in the flexor tendons and at the fingertip were recorded. A rupture of the A4 pulley occurred most often in the crimp grip position (50%) but did not occur in the slope grip position, in which alternative events were the most common (67%). The forces in the deep flexor tendon (FDP) (slope grip: 371 N, crimp grip: 348 N) and at the fingertip (slope grip: 105 N, crimp grip: 161 N) were not significantly different between the 2 finger positions, but the forces acting on the pulleys were higher in the crimp grip position (A2 pulley: 287 N, A4 pulley: 226 N) than in the slope grip position (A2 pulley: 121 N, A4 pulley: 103 N). The crimp grip position may be the main cause for A4 pulley ruptures but the slope grip position may be hazardous for other injuries as the forces recorded in the flexor tendons and at the fingertip were comparable at the occurrence of a terminal event.

The rapid evolution of human immunodeficiency virus (HIV) envelope represents a major challenge to vaccine and drug development, particularly because the underlying mechanisms are not completely understood. To explore whether distinct patterns of positive selection within the envelope glycoprotein (gp) 120 exist and are associated with functionally relevant domains, we conducted a long-term survey of sequence evolution in 20 HIV-1-infected persons who interrupted antiretroviral therapy. In total, 1753 clonal sequences encompassing the C2-V3-C3 region of gp120 were derived. Strikingly, positively selected amino acids mapped almost exclusively (P=.0003) to externally accessible residues on the gp120 crystal structure. The current understanding of envelope structure and function associates the main determinants of viral entry and the targets for neutralizing antibodies with these exterior regions of gp120, strongly suggesting that the observed adaptive evolution of these sites occurs in response to respective selective forces.

SummarySpecific and potent caspase inhibitors are indispensable for the dissection of the intricate pathways leading to apoptosis. We selected a designed ankyrin repeat protein (DARPin) from a combinatorial library that inhibits caspase-2 in vitro with a subnanomolar inhibition constant and, in contrast to the peptidic caspase inhibitors, with very high specificity for this particular caspase. The crystal structure of this inhibitor (AR_F8) in complex with caspase-2 reveals the molecular basis for the specificity and, together with kinetic analyses, the allosteric mechanism of inhibition. The structure also shows a conformation of the active site that can be exploited for the design of inhibitory compounds. AR_F8 is a specific inhibitor of an initiator caspase and has the potential to help identify the function of caspase-2 in the complex biological apoptotic signaling network.

This study investigates the changes of the connective tissue in the fingers of performance sport climbers resulting after a minimum of 15 years of climbing. Evaluation was performed by ultrasonography on the palmar side of the fingers (Dig) II-V to measure the thickness of the A2 and A4 annular pulleys, the flexor digitorum superficialis (FDS) and profundus (FDP) tendons and the palmar plates (PP's) of the proximal interphalangeal (PIP) as well as distal interphalangeal (DIP) joint in sagittal and axial direction. Totally, 31 experienced male sport climbers (mean age 37y, 30-48y grade French scale median 8b, range 7b+ to 9a+) participated in the study. The control-group consisted of 20 male non-climbers (age 37y, 30-51y). The A2 and A4 pulleys in climbers were all significantly thicker (A2 Dig III 62%, Dig IV 69%; A4 Dig III 69%, Dig IV 76%) as compared to non-climbers pulleys. All PP's of the DIP joints were also significantly thicker, particularly at Dig III and IV (76 and 67%), whereas the PP's at PIP joints were only scarce significant for three joints. Differences of the diameter of the flexor tendons were less distinct (1-21%) being significant only over the middle phalanx. High load to the fingers of rock climbers after a minimum of 15 years of climbing years induced considerable connective tissue adaptions in the fingers, most distinct at the flexor tendon pulleys and joint capsule (PP) of the DIP joints and well detectable by ultrasound.

The accurate reduction of tibial plateau malunions can be challenging without guidance. In this work, we report on a novel technique that combines 3-dimensional computer-assisted planning with patient-specific surgical guides for improving reliability and accuracy of complex intraarticular corrective osteotomies. Preoperative planning based on 3-dimensional bone models was performed to simulate fragment mobilization and reduction in 3 cases. Surgical implementation of the preoperative plan using patient-specific cutting and reduction guides was evaluated; benefits and limitations of the approach were identified and discussed. The preliminary results are encouraging and show that complex, intraarticular corrective osteotomies can be accurately performed with this technique. For selective patients with complex malunions around the tibia plateau, this method might be an attractive option, with the potential to facilitate achieving the most accurate correction possible.

Purpose To present results regarding the accuracy of the reduction of surgically reconstructed scaphoid nonunions or fractures using 3-dimensional computer-based planning with and without patient-specific guides. Methods Computer-based surgical planning was performed with computed tomography (CT) data on 22 patients comparing models of the pathological and the opposite uninjured scaphoid in 3 dimensions. For group 1 (9 patients), patient-specific guides were designed and manufactured using additive manufacturing technology. During surgery, the guides were used to define the orientation of the reduced fragments. The scaphoids in group 2 (13 patients) were reduced with the conventional freehand technique. All scaphoids in both groups were fixed with a headless compression screw or K-wires, and all bone defects (except one) were filled with autologous bone grafts or vascularized grafts. Postoperative CT scans were acquired 2 or more months after the operations to monitor consolidation and compare the final result with the preoperative plan. The clinical results and accuracy of the reconstructions were compared. Results In group 1, 8 of 9 scaphoids healed after 2 to 6 months, and partial nonunion after 9 months was observed in one patient. In group 2, 11 of 13 scaphoids healed between 2 and 34 months whereas 2 scaphoids did not consolidate. Comparison of the preoperative and postoperative 3-dimensional data revealed an average residual displacement of 7° (4° in flexion-extension, 4° in ulnar-radial deviation, and 3° in pronation-supination) in group 1. In group 2, residual displacement after surgery was 26° (22° in flexion-extension, 12° in ulnar-radial deviation, and 7° in pronation-supination). The difference in the accuracy of reconstruction was significant. Conclusions Although the scaphoid is small, patient-specific guides can be used to perform scaphoid reconstructions. When the guides were used, the reconstructions were significantly more anatomic compared with those resulting from the freehand technique. Type of study/level of evidence Therapeutic III.

The cell death protease caspase-2 has recently been recognized as the most apical caspase in the apoptotic cascade ignited during cell stress signaling. Cytotoxic stress, such as that caused by cancer therapies, leads to activation of caspase-2, which acts as a direct effector of the mitochondrion-dependent apoptotic pathway resulting in programmed cell death. Here we report the x-ray structure of caspase-2 in complex with the inhibitor acetyl-Leu-Asp-Glu-Ser-Asp-aldehyde at 1.65-A resolution. Compared with other caspases, significant structural differences prevail in the active site region and the dimer interface. The structure reveals the hydrophobic properties of the S5 specificity pocket, which is unique to caspase-2, and provides the details of the inhibitor-protein interactions in subsites S1-S4. These features form the basis of caspase-2 specificity and allow the design of caspase-2-directed ligands for medical and analytical use. Another unique feature of caspase-2 is a disulfide bridge at the dimer interface, which covalently links the two monomers. Consistent with this finding, caspase-2 exists as a (p19/p12)2 dimer in solution, even in the absence of substrates or inhibitors. The intersubunit disulfide bridge stabilizes the dimeric form of caspase-2, whereas all other long prodomain caspases exist as monomers in solution, and dimer formation is driven by ligand binding. Therefore, the central disulfide bridge appears to represent a novel way of dimer stabilization in caspases.

Purpose To investigate the reduction accuracy of 3-dimensional planned single-cut osteotomies (SCOTs) of the forearm that were performed using patient-specific guides. Methods A retrospective analysis of SCOTs performed between 2012 and 2014 was performed. Ten patients (age, 15–59 years) with 6 malunions of the ulna and 6 malunions of the radius were identified. The reduction accuracy was assessed by comparing the 3-dimensional preoperative plan of each osteotomy with the superimposed bone model extracted from postoperative computed tomography data. The difference was assessed by 3-dimensional angle and in all 6 degrees of freedom (3 translations, 3 rotations) with respect to an anatomical coordinate system. Wrist range of motion and grip strength was assessed after a mean of 16.7 months and compared with the preoperative measurements. Results On average, the 12 SCOTs demonstrated excellent accuracy of the reduction with respect to rotation (ie, pronation/supination, 4.9°; flexion/extension, 1.7°; ulnar/radial angulation, 2.0°) and translation (ie, proximal/distal, 0.8 mm; radial/ulnar, 0.8 mm; dorsal/palmar, 0.8 mm). A mean residual 3-dimensional angle of 5.8° (SD, 3.6°) was measured after surgery. All 6 patients operated on for reasons of a reduced range of motion demonstrated improved symptoms and increased movement (from 20° to 80°). In the patients with unstable/painful distal radioulnar joint, 3 were totally free of complaints and 1 patient showed residual pain during sports. Conclusions A SCOT combined with patient-specific guides is an accurate and reliable technique to restore normal anatomy in multiplanar deformities of the forearm. Type of study/level of evidence Therapeutic IV.

New 3-dimensional supported technologies considerably improved accuracy of corrective osteotomies and allowed alignments of cuts not possible before. The introduction of simply applicable software made it possible also for not in informatics educated persons to segment CT data, generate 3D models of bones and compare them with the mirrored opposite side. Only this approach allows an exact analysis of deformation, the creation of an operation plan and the virtual performance of the procedure in 3D. The production of individualized drilling and sawing guides which fit defined and unique to the bone surface by laser sintering technique permits an exact implementation of the planning to the operation. The technique is presented on the basis of cases of the forearm and hand.Neue 3-dimensionale (3D) unterstützte Techniken erlauben es, das seit Jahrzehnten unveränderte Vorgehen bei Korrekturosteotomie wesentlich zu verbessern sowie komplexe Schnittführungen durchzuführen, die zuvor nur schwierig zu kontrollieren waren. Die Einführung von leicht bedienbarer Software ermöglicht auch Benutzern ohne spezielle Vorkenntnisse CT-Daten am Computer zu segmentieren, 3D Modelle von Knochen herzustellen und diese mit der gespiegelten Gegenseite zu vergleichen. Erst dieses Vorgehen erlaubt eine exakte Fehlstellungsanalyse, das Erstellen eines Operationsplanes und die virtuelle Durchführung der Operation in 3D. Das Herstellen von individualisierten Bohr- und Sägelehren mit dem Laser-Sinterverfahren (3D Drucker), welche in eindeutiger und bestimmter Position auf der jeweiligen Knochenoberfläche angelegt werden können, ermöglicht die exakte Umsetzung der Planung in der Operation. Die Technik soll anhand von Fallbeispielen an Vorderarm und Hand vorgestellt werden.

The objectives of this study were the evaluation of flexor tendon pulley rupture of the fingers in the crimp grip position using magnetic resonance imaging (MRI) and the comparison of the results with MRI in the neutral position in a cadaver study. MRI in the crimp grip position and in the neutral position was performed in 21 cadaver fingers with artificially created flexor tendon pulley tears (combined pulley rupture, n = 14; single pulley rupture, n = 7). Measurement of the distance between the tendon and bone was performed. Images were evaluated by two readers, first independently and in cases of discrepancy in consensus. Sensitivity and specificity for detecting combined pulley ruptures were calculated. Tendon bone distances were significantly higher in the crimp grip position than in the neutral position. Sensitivity and specificity for detecting combined pulley rupture were 92.86 % and 100 % respectively in the crimp grip position and 78.57 % and 85.71 % respectively in the neutral position. Kappa values for interobserver reliability were 0.87 in the crimp grip position and 0.59 in the neutral position. MRI examination in the crimp grip position results in higher tendon bone distances by subjecting the pulleys to a higher strain, which facilitates image evaluation with higher interobserver reliability, higher sensitivity, and higher specificity for combined pulley rupture compared with examination in the neutral position.

OBJECTIVE.:The purpose of this article is to analyze the MR anatomy and variable imaging characteristics of the thumb in asymptomatic volunteers.MRI of the thumb was obtained in 34 asymptomatic volunteers (mean age, 33.9 ± 9.2 years). Two radiologists independently assessed visibility and signal intensity (SI) and thickness of the following structures of the metacarpophalangeal and interphalangeal joints: proper and accessory radial and ulnar collateral ligaments, volar and dorsal plates, adductor pollicis aponeurosis, and annular pulleys. The presence and size of a synovial recess at the base of all plates was assessed.On intermediate-weighted fat-saturated images, the ulnar collateral ligament of the metacarpophalangeal joint (reader 1, 79%; reader 2, 62%) and the adductor pollicis aponeurosis (reader 1, 50%; reader 2, 82%) commonly had a striated appearance. The radial collateral ligament of both joints was mainly of low SI (metacarpophalangeal joint, 53% for reader 1 and 85% for reader 2; interphalangeal joint, 59% for reader 1 and 82% for reader 2). All four pulleys were visible in each volunteer. An intermediate SI was observed in almost all pulleys, whereas the variable annular pulley had predominantly a low SI (reader 1, 50%; reader 2, 74%). The ulnar collateral ligament of the metacarpophalangeal joint is typically less than 3 mm thick, and the radial collateral ligament is less than 2 mm thick. A full-thickness synovial recess at the base of the dorsal plate of the metacarpophalangeal joint was seen in almost all volunteers (reader 1, 97%; reader 2, 100%).The ligaments and pulleys of the thumb show considerable variability on MRI in healthy volunteers. The ulnar collateral ligament of the metacarpophalangeal joint is typically striated and less than 3 mm thick. A full-thickness synovial recess at the base of the dorsal plate of the metacarpophalangeal joint is a normal finding and should not be misdiagnosed as a tear.

Circular taping around the proximal phalanx is frequently used by rock climbers to treat tenosynovitis and to prevent injuries to the A2 pulley. The aim of this study was to determine the biomechanical effectiveness of such taping. Devices were built to measure physiological bowstringing in vivo, and to determine the force of bowstringing as well as the force applied to the pulley tape. Two kinds of taping on 16 fingers were measured during the typical crimp grip position. Taping over the A2 pulley decreased bowstringing by 2.8% and absorbed 11%of the force of bowstringing. Taping over the distal end of the proximal phalanx decreased bowstringing by 22% and absorbed 12% of the total force. Circular taping is minimally effective in relieving force on the A2 pulley. It is probably ineffective in preventing pulley ruptures.

New technologies improved the techniques of osteotomies, which remained over decades unchanged, and made bone cuts possible, which earlier on hardly were feasible. The introduction of simple applicable software can process CT data on a PC to reconstruct 3D models of a bone and to compare its shape with the mirror of the opposite side. This first allows an exact analysis of a malunion, the development of a plan for the correction and finally the virtual performance of the operation. The production of individualised drill-an saw-guides with the laser-sintering process (3D printer) which can be definitely positioned on the surface of the bone, implements exactly the planning into the operation. The new possibilities of this ostetomy technique are presented with 4 examples/cases from the hand surgery.Neue Technologien erlauben es, die seit Jahrzehnten unveränderten Arbeitsweisen der Osteotomie wesentlich zu verbessern sowie zuvor kaum durchführbare Schnittführungen zu ermöglichen. Die Einführung von einfach bedienbarer Software zur Verarbeitung von CT-Daten erlaubt es am PC 3D-Modelle von Knochen herzustellen und diese mit dem Spiegelbild der Gegenseite zu vergleichen. Erst dies erlaubt eine exakte Fehlstellungsanalyse, das Erstellen eines Operationsplanes und die virtuelle Durchführung der Operation. Das Herstellen von individualisierten Bohr- und Sägelehren im Laser-Sinterverfahren (3D-Print), die eindeutig auf der jeweiligen Knochenoberfläche positioniert wird, ermöglicht die exakte Umsetzung der Planung während der Operation. Anhand von Fallbeispielen aus der Handchirurgie sollen die neuen und erweiterten Möglichkeiten der heutigen Osteotomie dargelegt werden.Demeurées inchangées pendant des décades, les techniques de l'ostéotomie ont été améliorées, permettant aujourd'hui de couper l'os d'une manière pratiquement irréalisable auparavant. L'introduction d'un programme informatique simple d'emploi permet de traiter les données obtenues par CT et de reconstruire un modèle de l'os en trois dimensions et ainsi de comparer avec l'image en miroir du côté controlatéral. Cela permet tout d'abord une analyse précise d'une mauvaise congruence, le développement d'un plan de correction et finalement l'évaluation virtuelle du résultat de l'opération. La production d'un gabarit de perçage ou de sciage avec la technique de laser-sintering permet de positionner exactement les plans de coupe pendant l'opération. Les nouvelles possibilités offertes par cette technique d'ostéotomie sont illustrées par 4 cas ayant trait à la chirurgie de la main.