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Nerve injuries of the upper extremity can cause significant motor and sensory deficits that may lead to personal suffering and work disability with increased healthcare costs. The aim of this study was to describe the epidemiology of nerve injuries of the upper extremity in the whole population of Finland (1998–2016). Data based on diagnosis codes were obtained from the Care Register for Health Care, including incident cases of median, radial, ulnar, musculocutaneous, axillary, and digital nerves. Age- and gender-specific incidence rates, both crude and standardised (for the European normal population in 2011), were calculated as well as the level of the nerve injuries in the upper extremity. Our study included 13,458 patients with upper extremity nerve injury. The mean standardised incidence rate of any upper extremity nerve injury was 1.18 among men and 0.05 among women per 100,000 person-years over the study period. The incidence peaked among men at working age. The most common nerve injury level was the fingers and thumb, with 5,533 cases and mean standardised incidence rates per 100,000 person-years of 0.51 among men and 0.19 among women.

Background Scapholunate advanced collapse (SLAC) and scaphoid non-union advanced collapse (SNAC) are common types of wrist osteoarthritis (OA). Non-operative treatment consists of pain medication, splinting, and avoiding activities that induce pain. However, in case a course of conservative treatment is unsuccessful, operative treatment is needed. The two most conventional operative approaches for SLAC/SNAC OA are four-corner arthrodesis (FCA) and proximal row carpectomy (PRC). Although FCA is the gold-standard operative technique and may lead to superior grip strength, the evident benefit of PRC is that it obviates any need for hardware removal and controlling for bony union. To date, no high-quality randomized controlled trial comparing FCA and PRC exists. As clinical outcomes seem comparable, a trial that assesses patient-reported outcomes, adverse events, and secondary operations may guide clinical decision making between these two procedures. Thus, the aim of this multi-institutional double-blind randomized controlled trial is to study whether PRC is non-inferior to FCA in treating SLAC/SNAC OA. Methods The trial is designed as a randomized, controlled, patient- and outcome-assessor blinded multicenter, two-armed 1:1 non-inferiority trial. Patients with SLAC/SNAC-induced wrist pain meeting trial inclusion criteria will undergo wrist arthroscopy to further assess eligibility. Each patient eligible for the trial will be randomly assigned to undergo either FCA or PRC. The primary endpoint of this study is the Patient Rated Wrist Evaluation (PRWE) at 1-year after FCA versus PRC. Secondary outcomes include Quick-Disabilities of the Arm, Shoulder and Hand, EQ-5D-5L, pain, grip strength, wrist active range of motion, radiographic evaluation, and adverse events. Trial design, methods, and statistical analysis plan will be presented here. Discussion We present an RCT design comparing FCA vs PRC for SLAC/SNAC-induced OA. The results of this trial will assist in decision making when planning surgery for SLAC/SNAC. Trial registration: ClinicalTrials.gov NCT04260165. Registered February 7, 2020.

This current Special Issue of JCM will highlight some of the latest studies on carpal tunnel syndrome (CTS) [...]

Background Trigger finger is a common hand disorder that limits finger range of motion and causes pain and snapping of the affected finger. Trigger finger is caused by an imbalance of the tendon sheath and the flexor tendon. The initial treatment is generally a local corticosteroid injection around the first annular (A1) pulley. However, it is not unusual that surgical release of the A1 pulley is required. Moreover, adverse events after local corticosteroid injection or operative treatment may occur. Platelet-rich plasma (PRP) has been shown to be safe and to reduce symptoms in different tendon pathologies, such as DeQuervain’s disease. However, the effects of PRP on trigger finger have not been studied. The aim of this single-center triple-blind randomized controlled trial is to study whether PRP is non-inferior to corticosteroid injection in treating trigger finger. The secondary outcome is to assess the safety and efficacy of PRP in comparison to placebo. Methods The trial is designed as a randomized, controlled, patient-, investigator-, and outcome assessor-blinded, single-center, three-armed 1:1:1 non-inferiority trial. The patients with clinical symptoms of trigger finger will be randomly assigned to treatment with PRP, corticosteroid, or normal saline injection. The primary outcome is Patient-Rated Wrist Evaluation and symptom resolution. Secondary outcomes include Quick-Disabilities of the Arm, Shoulder and Hand; pain; grip strength; finger active range of motion; and complications. Appropriate statistical methods will be applied. Discussion We present a novel RCT study design on the use of PRP for the treatment of trigger finger compared to corticosteroid and normal saline injection. The results of the trial will indicate if PRP is appropriate for the treatment of trigger finger. Trial registration ClinicalTrials.gov NCT04167098. Registered on November 18, 2019.

Study Design Cross-sectional study. Introduction There is a lack of information on the measurement properties of patient-reported upper extremity instruments and their association to health-related quality of life (HRQoL). Purpose of the Study This study aimed to examine and compare the measurement properties and construct validity of the Disabilities of Arm, Shoulder, and Hand (DASH) Instrument and the Michigan Hand Questionnaire (MHQ) using a heterogeneous sample of patients with hand and wrist problems. Methods Two hundred fifty consecutive patients visiting a general orthopedic outpatient clinic due to various hand/wrist problems were invited to participate in the study. A total of 193 (77%) participants provided sufficient patient-reported outcome data and were included in the analysis. Participants completed the DASH, the MHQ, the EQ-5D-3L, and pain on a visual analog scale instruments. Grip and key pinch forces were measured. Scale targeting, relatedness of demographics, and construct validity of the DASH and the MHQ were assessed. Results Both the DASH and the MHQ had good targeting, but the DASH had wider coverage. The convergence between the DASH and the MHQ was high. The DASH was more closely related to HRQoL than the MHQ in terms of EQ-5D scores. Discussion The DASH instrument appeared to measure hand function and disability from a perspective of HRQoL superior to the MHQ among patients with heterogeneous hand and wrist complaints. Conclusion The DASH performs well in measuring the HRQoL-related hand outcomes while the MHQ might be more specific for the affected hand.

Introduction The construct validity of the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH) has previously been questioned. The purpose of this study was to evaluate the measurement properties of the Finnish version of the DASH for assessing disability in patients with hand complaints using Rasch Measurement Theory. Methods A cohort of 193 patients with typical hand and wrist complaints were recruited at a surgery outpatient clinic. The DASH scores were analysed using the Rasch model for differential item functioning, unidimensionality, fit statistics, item residual correlation, coverage/targeting and reliability. Results In the original DASH questionnaire, the item response thresholds were disordered for 2 of 30 of the items. The item fit was poor for 9 of 30 of the items. Unidimensionality was not supported. There was substantial residual correlation between 87 pairs of items. Item reduction (chi square 95, degrees of freedom 50, p Conclusion Unidimensionality of the original Finnish version of the DASH was not supported, meaning the questionnaire seems to gauge traits other than disability alone. Hence, the clinician must be careful when trying to measure change in patients’ scores. Item reduction or the creation of testlets did not lead to good alternatives for the original Finnish DASH. Differential item functioning showed that the original Finnish scale exhibits minor response bias by age in one item. The original Finnish DASH covers different levels of ability well among typical hand surgery patients.

Carpal tunnel syndrome (CTS) is the most common median nerve compression neuropathy. Its symptoms and clinical presentation are well known. However, symptoms at median nerve distribution can also be caused by a proximal problem. Pronator syndrome (PS) and anterior interosseous nerve syndrome (AINS) with their typical characteristics have been thought to explain proximal median nerve problems. Still, the literature on proximal median nerve compressions (PMNCs) is conflicting, making this classic split too simple. This review clarifies that PMNCs should be understood as a spectrum of mild to severe nerve lesions along a branching median nerve, thus causing variable symptoms. Clear objective findings are not always present, and therefore, diagnosis should be based on a more thorough understanding of anatomy and clinical testing. Treatment should be planned according to each patient’s individual situation. To emphasize the complexity of causes and symptoms, PMNC should be named proximal median nerve syndrome.

A distal radius fracture (DRF) is one of the most common fractures in emergency units, the treatment of which requires considerable health care resources. We analyzed the incidence rate for DRFs and the incidence rate of operative treatment over a five-year period, 2015–2019, for the entire population of Finland and all ages. Data was obtained from the Finnish National Care Register for Health Care. The results were counted as cases per 100,000 person/years and standardized with the European Standard Population 2013. The mean annual incidence rate of DRF was 204.90 (203.21–206.59) in specialist care and 69.53 (68.55–70.52) in primary care. It peaked among the pediatric population and among elderly women, in whom it was more than four times as common compared to men of the same age. No increase in the incidence rate of DRFs was found. The mean incidence rate of operative treatment was 45.66 (45.66–45.66)/100,000 person/years, 2015–2019; women were more likely to undergo operative treatment. Altogether, 15–18% of DRFs were operated on over the study period. The annual incidence rate of operations seemed to plateau compared to earlier studies in Finland.

Objectives: Carpal tunnel syndrome (CTS) causes a considerable amount of sick leave and healthcare costs. The etiology of CTS is multifactorial, involving both personal and occupational risk factors. To date, few prospective cohort studies on occupational risk factors of CTS have examined the general working population. Methods: The study population consisted of participants from the Northern Finland Birth Cohort of 1966 who attended the 31-year follow-up in 1997 and were working ≥3 days a week in a paid job (N=6326). Information on socio-economic status, weight and height, smoking, exposure to occupational physical factors, and long-term illnesses was collected at baseline in 1997. Data on hospitalizations due to CTS came from the Care Register for Health Care, 1997–2016. Results: Between 1997 and 2016, 3.4% of the participants had been hospitalized (attended secondary care) for CTS. After adjusting for confounders, women [hazard ratio (HR) 3.77, 95% confidence interval (CI) 2.70–5.25], overweight/obese participants (HR 1.69, 95% CI 1.29–2.22), smokers (HR 1.48, 95% CI 1.12–1.96), farmers and manual workers (HR 3.02, 95% CI 1.85–4.92 compared with upper clerical workers), lower clerical workers (HR 1.74, 95% CI=1.08–2.80), workers exposed to hand vibration (HR 2.29, 95% CI 1.48–3.54) and participants with physically demanding jobs (HR 1.71, CI 1.06–2.76) were at increased risk of hospitalization for CTS. Physically demanding work increased the risk of hospitalization for CTS for overweight/obese participants at baseline, but not for participants of normal weight. Conclusions: Excess body mass and occupational physical factors increase the risk of hospitalization for CTS. Excess body mass potentiates the adverse effects of strenuous work on CTS.

To date, the role of smoking in carpal tunnel syndrome (CTS) is unclear. The aim of this systematic review and meta-analysis was to assess the association between smoking and CTS. The literature searches were conducted in PubMed, Embase, and Scopus, from inception until October 2021. Three reviewers screened the titles, abstracts, and full-text articles and evaluated the methodological quality of the included studies. A random-effects meta-analysis was used, and heterogeneity across studies was examined using I2 statistic. A total of 31 (13 cross-sectional, 10 case-control, and 8 cohort) studies were qualified for meta-analysis. In a meta-analysis of cohort studies, the risk of CTS did not differ between current and never smokers (pooled hazard ratio (HR) 1.09, 95% CI 0.84–1.43), current and past/never smokers (HR 1.07, 95% CI 0.94–1.23), and past and never smokers (HR 1.12, 95% CI 0.83–1.49). Furthermore, a meta-analysis of case control studies found no difference in the risk of CTS between current and never smokers (pooled odds ratio (OR) 0.92, 95% CI 0.56–1.53), current and past/never smokers (OR 1.10, 95% CI 0.51–2.36), and past and never smokers (OR 0.91, 95% CI 0.59–1.39). However, a meta-analysis of cross-sectional studies showed the associations of ever (OR 1.36, 95% CI 1.08–1.72) and current smoking (OR 1.52, 95% CI 1.11–2.09) with CTS. However, the association between ever smoking and CTS disappeared after limiting the meta-analysis to higher quality studies or after adjusting for publication bias. The association between current smoking and CTS also attenuated after limiting the meta-analysis to studies that confirmed CTS by a nerve conduction study or studies with low attrition bias. This meta-analysis does not support an association between smoking and CTS. The association between smoking and CTS observed in cross-sectional studies could be due to biases and/or confounding factors.

Ulnar nerve entrapment (UNE) is the second most common entrapment neuropathy in the upper extremity. The aetiology of UNE is multifactorial and is still not fully understood. The aim of the study was to identify occupational risk factors for UNE and to determine whether smoking modifies the effects of work-related factors on UNE. The study population consisted of the Northern Finland Birth Cohort of 1966 (NFBC1966). In total, 6325 individuals active in working life participated in a 31-year follow-up study in 1997. Occupational risk factors were evaluated by a questionnaire at baseline in 1997. The data on hospitalizations due to UNE were obtained from the Care Register for Health Care between 1997 and 2018. The incidence rate of hospitalization due to UNE was 47.6 cases per 100 000 person-years. After adjusting for confounders, entrepreneurs (Hazard ratio (HR)=3.68, 95% CI 1.20-11.27), smokers (HR=2.51, 95% CI 1.43-4.41), workers exposed to temperature changes (HR=1.72, 95% CI 1.00-2.93), workers with physically demanding jobs (HR=3.02, 95% CI 1.39-6.58), and workers exposed to hand vibration (HR=1.94, 95% CI 1.00-3.77) were at an increased risk of hospitalization for UNE. Exposure to work requiring arm elevation increased the risk of hospitalization due to UNE among smokers (HR=2.62, 95% CI 1.13-6.07), but not among non-smokers. Work-related exposure to vibration and temperature changes, and physically demanding work increase the risk of hospitalization for UNE. Smoking may potentiate the adverse effects of work-related factors on UNE.

Background and Aims: Michigan Hand Outcomes Questionnaire is a widely used patient-reported outcome measure in hand surgery. The aim of this study was to translate and validate the Michigan Hand Outcomes Questionnaire into Finnish for Finnish patients with hand problems following international standards and guidelines. Material and Methods: The original English Michigan Hand Outcomes Questionnaire was translated into Finnish. Altogether, 115 patients completed the Finnish Michigan Hand Outcomes Questionnaire, and reference outcomes: Disabilities of the Arm and Shoulder, EQ-5D 3L and pain intensity on a visual analog scale. Grip and key pinch forces were measured. After 1–2 weeks, 63 patients completed the Finnish Michigan Hand Outcomes Questionnaire the second time. The Michigan Hand Outcomes Questionnaire was analyzed for internal consistency, repeatability, correlations with the reference outcomes, and factor analysis. Results: Cronbach’s alpha ranged from 0.90 to 0.97 in all the Michigan Hand Outcomes Questionnaire subscales, showing high internal consistency. The intraclass correlation coefficient showed good to excellent test–retest reliability ranging from 0.66 to 0.91 in all the Michigan Hand Outcomes Questionnaire subscales. In factor analysis, the structure with six subscales was not confirmed. All the subscales correlated with Disabilities of the Arm and Shoulder score, and five subscales correlated with EQ-5D index. Conclusion: The Finnish version of the Michigan Hand Outcomes Questionnaire showed similar properties compared to the original English version and thus can be used as patient-reported outcome measure for Finnish patients with hand problems.

The aim of this study was to investigate the incidence rates and operations for carpal tunnel syndrome and ulnar and radial neuropathies in specialist care in Finland. Patients diagnosed with entrapment neuropathies of the upper extremity were identified from the Care Register for Health Care, 2007–2016. There were 81,911 cases in 54,095,070 person-years. The total crude incidence rates per 100,000 person-years among women and men were 197 and 105 for carpal tunnel syndrome, 26 and 36 for ulnar neuropathies, and 5.7 and 8.5 for radial neuropathies, respectively. Of these, carpal tunnel syndrome was operated on in 63% of women and 61% of men, ulnar neuropathy in 43% of women and 47% of men, and radial neuropathy in 11% of women and 8% of men. Incidence of carpal tunnel syndrome and ulnar neuropathies increased up to late middle age, while radial neuropathies were less common. Level of evidence: III

Ulnar nerve entrapment is the second most common compression neuropathy of the upper extremity. It has been associated with smoking in cross-sectional studies. Our aim was to study whether smoking is associated with ulnar nerve entrapment. The study population consisted of the Northern Finland Birth Cohort 1966 participants, who attended the 31-year follow-up in 1997 (N = 8,716). Information on smoking, body mass index (BMI), long-term illnesses, and socio-economic status were recorded at baseline in 1997. Data on hospitalizations due to ulnar nerve entrapment neuropathies was obtained from the Care Register for Health Care, 1997–2016. Hazard ratios (HR) with 95% confidence intervals (CI) and population attributable risk (PAR) were calculated adjusted for gender, BMI and socio-economic status. 66 patients were diagnosed with ulnar nerve entrapment in the follow-up 1997–2016. Before the age of 31 years, smoking ≤10 pack years associated with more than doubled (HR = 2.57, 95% CI = 1.29–5.15) and smoking >10 pack years with more than five-folded (HR = 5.61, 95% CI = 2.80–11.23) risk for ulnar nerve entrapment compared to non-smokers in the adjusted analyses. Adjusted PAR for smoking (reference of no smoking) was 53.6%. In our study, smoking associated with increased risk for ulnar nerve entrapment, accounting for considerable proportion of increased risk.

Background: The repair of a segmental peripheral nerve injury is a clinical challenge. Several studies have been performed to determine superior methods for overcoming nerve gaps. The purpose of this study was to investigate if the inside-out slided epineurium of the distal segment of an injured nerve can serve as a conduit to bridge a short nerve defect (10 mm). Methods: Nineteen sciatic nerves in Sprague–Dawley rats were transected, and a 10-mm gap was left between the ends. A section of distal epineurium was pulled inside out to bridge the gap. Walking track analysis was performed, and the sciatic function index (SFI) was calculated. Wet muscle mass and withdrawal reflex were measured. The density of axon fibers at different levels of repaired nerves was determined, and histological analysis was performed at 16 weeks. Results: The mean SFI improved from −81.0 at 4 weeks to 36.3 at 16 weeks. The axon densities showed regeneration through the epineural tube, and 5 of the rats demonstrated a withdrawal reflex. The weight of the tibialis anterior muscle of the injured limb at 16 weeks was 59% that of the uninjured side. Conclusions: The distal epineural sheath tube provided a size-matched conduit between the nerve stumps, with no histological donor-site morbidity. Histologically, regeneration occurred through the epineural tube without neuroma formation, and functional recovery was comparable to that of previous studies of nerve repair techniques. Technique may be an addition to the armamentarium of tools used to treat segmental nerve defects.

Background: Our aim was to determine whether maternal smoking and offspring’s own smoking affect the offspring’s risk for carpal tunnel syndrome (CTS). Method: The study sample consisted of the Northern Finland Birth Cohort 1966 (N = 8703). Information on maternal smoking was collected from the participants’ mothers. At 31 years, information on smoking, body mass index, socioeconomic status, and long‐term illnesses were collected, combined with data of CTS diagnoses from the Care Register for Health Care (1997–2016). Results: Maternal smoking was not associated with increased risk of CTS in offspring. Before the age of 31 years, smoking ≤10 pack years (hazard ratio [HR] = 1.54, 95% confidence interval [CI] = 1.11–2.15) and >10 pack years (HR = 1.90; 95% CI = 1.20–3.01) among women, and >10 pack years (HR = 1.89; 95% CI = 1.14–3.12) among men was associated with CTS compared with nonsmokers. Conclusions: In this birth cohort, offsprings’ own smoking was associated with CTS; however, maternal smoking was not.

Dupuytren's contracture, a proliferative disease of unknown origin, is characterized by an abnormal fibroblast proliferation process. Evidence from numerous microRNA (miRNA) studies shows that miRNAs have a vital function in many biological processes, for instance, in cellular signaling networks, cell growth, tissue differentiation, and cell proliferation. Our aim was to characterize, to our knowledge for the first time, the miRNA-expression profile of Dupuytren's contracture. The miRNAs identified may have a function in the pathogenesis of Dupuytren's contracture by targeting and regulating important pathways. We compared the miRNA-expression profile of 29 Dupuytren's contracture patients with that of control samples (fibroblast cells and palmar fascia). Some of the miRNAs identified in our Dupuytren's contracture samples, including miR-29c, miR-130b, miR-101, miR-30b, and miR-140-3p, were found to regulate important genes related to the β-catenin pathway: WNT5A, ZIC1, and TGFB1. Expression profiles of these genes reanalyzed from published gene-expression data from similar patient material correlated with our miRNA results. Analysis was also performed for groups of patients with recurrent/non-recurrent and patients with hereditary/non-hereditary Dupuytren's contracture, but no significant differences appeared in miRNA-expression profiles of these groups. Identification of unique miRNA expression in Dupuytren's contracture may lead to the development of novel molecular therapy for its treatment.

Purpose Nickel-titanium (NiTi) has been proposed as an alternative material for flexor tendon core suture. To our knowledge, its suitability as a circumferential suture of flexor tendon repair has not been investigated before. The purpose of this ex vivo study was to investigate the biomechanical properties of NiTi circumferential repairs and to compare them with commonly used polypropylene. Methods Forty porcine flexor tendons were cut and repaired by simple running or interlocking mattress technique using 100 μm NiTi wire or 6-0 polypropylene. Results The NiTi circumferential repairs showed superior stiffness, gap resistance, and load to failure when compared to polypropylene repairs with both techniques. Conclusions Nickel-titanium wire seems to be a potential material for circumferential repair of flexor tendons.

Initially the strength of tendon repair depends only on the properties of the repair technique. Postoperatively tenomalacia may develop at the suture-tendon junction decreasing initial repair strength (7). With immobilization the strength of the tendon repair has been shown to decrease significantly within the first three weeks of healing (8). However, early passive (9) and especially early active motion (8, 10, 11) have been shown to prevent the initial weakening leading to progressively increasing repair strength starting from the time of repair. The initial strength of the repair depends on the material properties and knot security of the sutures as well as on the holding capacity of the suture grips of the tendon. The biomechanical properties of the suture depend on the material itself and can be improved by increasing the number of strands crossing the repair site (12) and the suture calibre (13, 14). The holding capacity of the repair of the tendon depends on the configuration (12, 15–17), size (18, 19), and number (20) of the grips. The flexor tendon repair can be regarded as a composite of the core and the peripheral sutures (21, 22) with both influencing significantly the repair strength. Lotz et al. (21) showed that in a repair consisting of the 2-strand modified Kessler 4-0 core suture and simple running 6-0 peripheral suture, the applied load was carried from 64% to 77% by the peripheral suture at its point of rupture. After failure of the peripheral suture the total force is transferred onto the core suture. If the holding capacity of the core suture is exceeded, but not its material strength, the repair may still increase in strength with concomitantly progressing gap formation (21, 23). Ultimate failure finally occurs either by suture pullout or, if the holding capacity of the suture grips of the tendon exceeds the material strength, by suture breakage (14, 23, 24). FLExOR TENDON FORCES

Rheumatoid arthritis most commonly affects the metacarpophalangeal (MCP) joints of the hand. Pyrolytic carbon MCP arthroplasty has lately provided a new alternative in the treatment of these patients, but reports in the literature are still few. Here, we report the mid-term results of seven such prostheses implanted in two elderly patients with rheumatoid arthritis. Pyrolytic carbon MCP arthroplasty was performed on three MCP joints in one patient and on four MCP joints in another patient. A specific postoperative mobilization protocol was applied. Range of motion, grip strength, and pinch strength were recorded, and radiographs were taken at three, six, and ten months postoperatively. Ten months after the operation, the operated joints were pain-free, and grip and pinch strengths had improved. On average, the passive range of motion had improved and the active range of motion had remained about the same. The joints were clinically stable. No adverse remodeling or bone resorption was observed radiographically. Ulnar deviation recurred in one of the two cases. These results suggest pyrolytic carbon MCP arthroplasty to be a noteworthy alternative in the treatment of MCP joints affected by rheumatoid arthritis. Early treatment, before the development of severe soft tissue destruction, seems to yield better results.

Introduction: This study evaluates the results of the new surgical treatment of complete acromioclavicular (ac) dislocations using coracoclavicular (cc) fixation with a shape memory metal C-hook implant. Materials and methods: Fifteen patients were prospectively analyzed. They all had a Tossy III ac dislocation due to trauma. The ac ligament was reinserted using a surgical bone anchor, and the position of the joint was restored by fixing it with a C-hook. After 3 months the C-hook was removed. Functional status, symptom severity, X-rays and patient satisfaction were analyzed during clinical control visits. The follow-up time was 1 year. Results: At 12 weeks, full shoulder function had been achieved by 93% of the patients. The final control visit showed full recovery of active ROM in all patients. Two patients had mild pain during certain movements. X-rays showed the precise anatomical position of ac joint with no statistically significant differences compared to the healthy side. Patient contentment was excellent in 14 cases and satisfactory in one case. The average sick-leave was 58 days, including the removal operation. Minor osteolysis of the clavicle was noticed in two patients. Conclusion: The new C-hook implant provides accurate anatomical reduction, conserves the articular surfaces and enables fast functional recovery with excellent patient contentment. Technically, the implant is easy to use. Based on this study, the C-hook presents a reliable novel treatment option in surgical ac repair.

Bone morphogenetic protein (BMP) has been shown to induce bone formation and union in long bone defects and nonunions. There are, however, no previous reports of BMP being used for ulnar nonunions. We report on five cases of resistant ulnar nonunions treated with a composite implant consisting of a biocoral frame, collagen carrier, and bovine BMP. Four diaphyseal and one olecranon ulnar nonunions were treated using BMP/coral implant combined with internal fixation. Additional autografting was used in three cases. All of the cases were challenging in their own ways: Three of the patients had been operated on earlier for their nonunion without success, one had a 40 mm bone loss, and one had a 9-month-old untreated olecranon fracture. After excision of the sclerotic surfaces of the nonunion, the gap was filled with autograft and a composite implant containing BMP. Fixation was done with a compression plate in the diaphyseal nonunions and with a tension band in the olecranon nonunion. Solid union was achieved in all five cases. No infections or other adverse effects were encountered. These preliminary results suggest that BMP-containing implants might be a feasible alternative or superior to autografting in the treatment of resistant ulnar nonunions.

Nitinol (NiTi) is a promising new tendon suture material with good strength, easy handling and good super-elastic properties. NiTi sutures were implanted for biocompatibility testing into the right medial gastrocnemius tendon in 15 rabbits for 2, 6 and 12 weeks. Additional sutures were implanted in subcutaneous tissue for strength measurements in order to determine the effect of implantation on strength properties of NiTi suture material. Braided polyester sutures (Ethibond) of approximately the same diameter were used as control. Encapsulating membrane formation around the sutures was minimal in the case of both materials. The breaking load of NiTi was significantly greater compared to braided polyester. Implantation did not affect the strength properties of either material.

The biocompatibility of an orthopedic implant depends on the effect of the implant on bone-forming cells, osteoblasts. Changes in osteoblastic proliferation, maturation and differentiation are important events in ossification that enable monitoring the effect of the implant. Transforming growth factor-beta (TGF-beta) is known to suppress osteoblast proliferation and, on the other hand, to induce the maturation and differentiation of osteoblasts. Moreover, osteoblasts produce TGF-beta, which is embedded in the bone matrix and activated by bone-resorbing osteoclasts. TGF-beta inhibits osteoclastic activity. Here, we show for the first time the effect of nickel titanium shape memory metal (NiTi) on osteoblastic cytokine expression. In this study, we measured the levels of TGF-beta with enzyme-linked immunosorbent assay (ELISA) from a ROS-17/2.8 osteosarcoma cell line cultured on different metal alloy discs. ELISA results were proportioned to total DNA content of the samples. We compared NiTi, to stainless steel (Stst), pure titanium (Ti) and pure nickel (Ni). The TGF-beta1/DNA value in the NiTi group (0.0007 +/- 0.0003) was comparable with those seen in the Stst (0.0008 +/- 0.0001) and Ti (0.0007 +/- 0.0001) groups. The concentration in the Ni group was lower (0.0006 +/- 0.0003), though not statistically significantly so. In addition, the effect of surface roughness on TGF-beta1 production was studied. We compared three different grades of roughness in three differently hot-rolled alloys: NiTi. hot-rolled at 950 degrees C. Ti alloy hot-rolled at 850 degrees C (TiI) and the same Ti alloy hot-rolled at 1,050 degrees C (TiII). We found that increasing roughness of the NiTi surface increased the TGF-beta1 concentration. On the other hand, all roughness groups of TiII showed low levels of TGF-beta1. while a rough TiI surface induced similar TGF-beta1, expression as rough NiTi. Further, these same measurements made with interleukine 6 (IL-6) were found to be under the detection limit in these cultures. We conclude that a rough NiTi surface promotes TGF-beta1 expression in ROS-17/2.8 cells.

Background and Aims:Bone morphogenetic protein (BMP) has been shown to induce bone formation and union in long bone defects and nonunions. We report a preliminary study of a composite implant consisting of a biocoral frame, carrier collagen and bovine BMP in the treatment of scaphoid nonunions.Material and Methods:Two proximal and eight waist area scaphoid nonunions were treated using BMP/coral implant combined with either the Matti-Russe procedure (2 cases) or an interpositional bone graft fixed with screws or compression fixation pins (8 cases). In two cases only a one piece BMP/coral implant was used as an interpositional graft and in other cases interpositional autograft was used with granular BMP/coral implant placed between the fragments and the graft.Results and Conclusions:Only two wrists resulted in complete union. These preliminary results suggest that composite implant of BMP, as used in the present study, may not solve the problems encountered in the treatment of scaphoid nonunions. Poor vascular conditions in scaphoid may not provide enough mandatory osteogenic cells for BMP to function properly. In avascular conditions coral does not resorb edequately and implants may also work as a sequester between the bone graft and the scaphoid bone and therefore actually inhibit the healing process.

Nitinol (NiTi) shape memory metal alloy makes it possible to prepare functional implants. A curved intramedullary NiTi nail has been shown to cause bending of the bone, bone thickening, increase in cortical area, and reduction in bone longitudinal growth. The purpose of the present study was to find out whether these changes are caused by the bending force of the curved nail or by the intramedullary nailing itself. Pre-shaped intramedullary NiTi nails were implanted in the cooled martensitic form into the medullary cavity of the right femur in 12 rats, where they started to restore their austenitic form, causing a bending force. Straight nails were used as controls in another 12 rats. After 12 weeks, the operated femurs were compared with their non-operated contralateral counterparts and the differences were compared between the groups. Anteroposterior radiographs demonstrated bone bowing only in the curved nail group. Retardation of longitudinal growth was observed in both groups, showing that the growth effect seems to be due to the intramedullary nailing itself. Increase in bone cross-sectional area and cortical thickness were found in both groups. However, this increase was more evident with the curved nail, indicating that the bending force of the functional nail seems to induce these changes.

Metallic osteosynthesis materials, i.e. implants used in the treatment of fractures and correction of bone position in children have traditionally been subsequently removed in a further operation. The necessity for the removal of orthopedic implants left completely under the skin is arguable and research-based evidence is scarce. Treatment practices vary. We present our literature- and experience-based recommendation on the removal of implants or leaving them in position. The removal of an implant should, however, always be decided on an individual basis.

A cDNA sequence of bone morphogenetic protein 3b (BMP-3b) of reindeer antler was produced with degenerative homology primers in polymerase chain reaction (PCR). An in situ hybridization study of BMP-3b mRNA in 1-month-old antler showed expression in most differentiated cells in the antler center. In addition, the bone-inductive capacity of the reindeer antler matrix was evaluated. Decalcified and powdered antler matrix of different stages of antler maturity was implanted in gelatin capsules under the rat dorsal muscle fascia for two implantation periods: 3 and 8 weeks. Allogenic matrix prepared from rat long bones was used as a positive control implant. Heterotopic ossification was evaluated histomorphometrically and densitometrically. Allogenic bone matrix induced rapid osteogenesis and mineral accumulation. Both endochondral and intramembranous ossification was evident, endochondral ossification being the dominant form. Mineral density in the induced ossicle was 115 +/- 48 mg/cm(3) as early as at 3 weeks and 350 +/- 69 mg/cm(3) at 8 weeks. The proportional areas of von Kossa-stained mineral were 3.67 +/- 2.1% and 11.6 +/- 0.07%, respectively. The antler preparations induced mineralization, but significantly less than the allogenic bone matrix. At 8 weeks, mineral density was significantly lower in the cast antler preparation than in the allogenic implants. The morphology of the mineralized areas of the antler preparations showed no ossification.

Nickel-titanium alloy (Nitinol) is a metallic biomaterial that has a unique thermal shape memory, superelasticity, and high damping properties. Nitinol is potentially very useful in orthopedic surgery, for example. At present, there are not enough confirmative biocompatibility data available on Nitinol. The aim of our study was to clarify the primary cytotoxicity and corrosion rate of Nitinol in human cell cultures. Comparisons were made with stainless steel (Stst), titanium (Ti), composite material (C), and control cultures with no test discs. Human osteoblasts (OB) and fibroblasts (FB) were incubated for 10 days with test discs of equal size, 6 x 7 mm. The cultures were photographed and the cells counted. Samples from culture media were collected on days 2, 4, 6, and 8, and the analysis of metals in the media was done using flameless atomic absorption spectrophotometry. The proliferation of FB was 108% (Nitinol), 134% (Ti) (p < 0.02), 107% (Stst), and 48% (C)(p < 0.0001) compared to the control cultures. The proliferation of OB was 101% (Nitinol), 100% (Ti), 105% (Stst), and 54% (C) (p < 0.025) compared to the controls. Initially, Nitinol released more nickel (129-87 micrograms/L) into the cell culture media than Stst (7 micrograms/L), but after 2 days the concentrations were about equal (23-5 micrograms/L versus 11-1 micrograms/L). The titanium concentrations from both Nitinol and Ti samples were all < 20 micrograms/L. We conclude that Nitinol has good in vitro biocompatibility with human osteoblasts and fibroblasts. Despite the higher initial nickel dissolution, Nitinol induced no toxic effects, decrease in cell proliferation, or inhibition on the growth of cells in contact with the metal surface.

Dupuytren's contracture forms nodules and fibril bundles causing the fingers to contract. The pathological tissue contains myofibroblasts exhibiting properties of fibrocytes and smooth muscle cell myoblasts. The disease has a clear-cut family predisposition, but its etiology remains unclear. Diabetes, smoking, heavy drinking and mechanical irritation of the palm are regarded as predisposing factors. Dupuytren's contracture is treated surgically in cases with the limitation of extension in the metacarpophalangeal joints over 30 degrees and 20 degrees in the proximal interphalangeal joints.

Two hundred and fifty children undergoing herniotomy or orchidopexy under general anaesthesia were randomly allocated to receive pre-operatively either diclofenac sodium 1 mg.kg-1 given intramuscularly or a caudal injection of bupivacaine 0.25% 1 ml.kg-1 with or without adrenaline or no analgesia. Plasma diclofenac and beta-endorphin concentrations were determined in eight and 21 patients respectively. Postoperative pain was assessed by ward nurses who were blinded to the group allocation. Comparison with the control group showed diclofenac to be an effective analgesic. Caudal bupivacaine provided more pain-free children during the early postoperative hours, but later the need for pethidine as rescue analgesic was lower among the children who had received intramuscular diclofenac. Caudal analgesia abolished the stress-induced increase in plasma beta-endorphin level which was found in the children given diclofenac and in those who served as controls. Total plasma clearance of intramuscular diclofenac sodium appears to be higher in children than in adults. A single intramuscular dose of diclofenac significantly reduces the need for an opioid analgesic in children after inguinal herniotomy or orchidopexy, and owing to its long duration of action, it offers an alternative or complementary method of pain relief to caudal analgesia.

Tendon repairs done with strong suture materials fail by suture pull out. To avoid pull out, suture loop needs to have a strong grip on the tendon. The aim of this study was to determine whether a single suture loop has a better grip of the tendon when multifilament or flat sutures are used compared with a conventional monofilament round suture. A cross-locking or simple grasping suture loop was placed into the distal end of a human cadaveric tendon using nitinol wire sutures in the following configurations: round monofilament (200 µm), round multifilament (4 × 100 µm), and flat multifilament (4 × 30 µm × 445 µm). The mean pull-out strength of the round multifilament (49.4 N) and flat multifilament sutures (50.7 N) were significantly higher than that of the round monofilament nitinol suture (36.5 N) when a locking loop was used. Suture grip can be improved by using a multifilament suture and a locking type of suture configuration.

Purpose New, stronger suture materials have been introduced for flexor tendon surgery. The advantage of these materials can be lost if the suture loop pulls out from the tendon. The aim of this study was to compare the ability of various locking loops to grip the tendon. Methods We inserted 4 different standard and 2 experimental locking loops with 200-μm nitinol wire into human cadaveric flexor digitorum profundus tendons. The standard loops were: group 1, cruciate; group 2, Pennington modified Kessler; group 3, cross-stitch; and group 4, Lim-Tsai. The experimental loops were: group 5, a composition of Pennington modified Kessler with a cross-stitch loop; and group 6, a locking Kessler type of loop with a superficial transverse component. We loaded the loops until failure. We recorded the pull-out strength and stiffness and documented failure mechanisms during the pull-out test. Results The cruciate loop had the weakest holding capacity, 20 N, which was significantly less than in groups 2 to 6. The cross-stitch loop, Lim-Tsai loop, and modified Kessler loop performed similarly (36 N, 37 N, and 39 N, respectively). The experimental loops had the highest pull-out strength (group 5, 59 N; and group 6, 60 N, both significantly greater than groups 1 to 4). The mode of failure was pull-out for all of the standard loops and 7 of the experimental loops. Of 20 experimental loops, 13 failed by suture rupture. Conclusions The 2 experimental loop configurations demonstrated higher pull-out strength and may have advantages when used with newer and stronger suture materials. The number of the locking components in the loops and the way the tension is transmitted to the tendon fibrils explain the results. Clinical relevance The loops presented in this study and that grip the tendon better may be useful with new materials that have high tensile strength.

Nickel-titanium shape memory alloy (NiTi) is a new suture material that is easy to handle, is strong, and biocompatible. The purpose of this study was to evaluate the material properties and biomechanical behaviour of 150 microm and 200 microm NiTi wires in flexor tendon repair. Braided polyester (4-0 Ethibond) was used as control. Fifty fresh-frozen porcine flexor tendons were repaired using the Pennington modification of the Kessler repair or a double Kessler technique. NiTi wires were stiffer and reached higher tensile strength compared to braided polyester suture. Repairs with 200 microm NiTi wire had a higher yield force, ultimate force and better resistance to gapping than 4-0 braided polyester repairs. Repairs made with 200 microm NiTi wire achieved higher stiffness and ultimate force than repairs made with 150 microm NiTi wire.

After replantation surgery it is helpful to use temperature monitoring in order to detect vascular problems early. One of the methods currently employed is to use a thermometer with a wired probe attached to the tissue being monitored. An infrared wireless thermometer, commonly used in industry, measures temperatures of surfaces without actually touching them. The purpose of this study was to evaluate the efficacy of infrared wireless thermometer technology for monitoring finger temperature. Finger temperatures of 38 volunteers were measured using the infrared wireless thermometer. A traditional wired thermometer was used as control. The measurements of both thermometers were similar when the temperature was 31.5 degrees and over, with no statistical differences (mean difference 0.06 degrees , P=0.521). At lower temperatures, however, the wireless infrared thermometer showed slightly lower temperature values (mean difference 1.01 degrees , P

Dupuytren's contracture (DC), a benign disease of unknown origin, is characterized by abnormal fibroblast proliferation and matrix deposition within the palmar and plantar faciae, causing contracture of the digits. Conventional cytogenetic studies of cultured fibroblast cells from DC nodules have revealed nonrecurrent, but usually normal, clonal (mainly +7, +8, and -Y, plus structural changes) and sporadic (nonclonal) numerical/structural rearrangements. No unique cytogenetic features of DC are known so far. We used 44K oligonucleotide-based array comparative genomic hybridization to obtain a wide pattern of chromosomal imbalances in 18 patients with DC. The genome-wide analysis revealed no changes of DNA copy number sequences. Accordingly, gene amplifications or deletions are apparently not involved in the progression of abnormal fibroblast proliferation and matrix deposition that lead to DC.

Objectives – The diagnostic utility and reliability of an easy-to-operate novel handheld nerve conduction tester in carpal tunnel syndrome (CTS) were evaluated. Materials and methods – Using the test device, the sensory nerve conductions (SNC) in the median and ulnar nerves were compared with each other in 194 patients with suspected CTS and 95 healthy controls. The test device results were compared with the results of nerve conduction studies (NCS) with traditional instrumentation. Results – The new device correctly classified 145 of the 149 hands (97.3%) without median nerve lesion and 171 of the 200 hands (85.5%) with median nerve lesions in traditional NCS. The specificity of the new tester compared with traditional instrumentation was 98%. The correlation coefficient for different technicians in different studies was 0.87. Conclusions – The findings obtained with the new tester in CTS were reliable and reproducible. This tester may increase availability of NCS in CTS.