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Background: Offset and leg length (LL) restoration are critical for the achievement of a stable, well-functioning hip following total hip arthroplasty (THA). Several techniques are described in the literature, including a hip calibration gauge. We question whether meticulous preoperative planning of a specific surgical technique in combination with the utilisation of a calibration gauge can provide an accurate offset and LL restoration. Methods: Retrospective review of 101 unilateral THAs via a posterior approach by a single surgeon. Preoperative radiographic LL and offset were radiographically calculated. Intraoperatively prior to hip dislocation a calibration gauge was used to measure LL and offset with a pin inserted into the iliac crest acting as a static referencing point. All had pelvis x-ray performed 6 weeks postoperatively. A literature review was conducted to establish average postoperative LL/offset values for statistical comparison. Results: The average absolute postoperative leg-length discrepancy (LLD) was 2.51 mm compared to preoperatively 3.54 mm ( p = 0.018). A total of 93.1% and 100% had LLD of ⩽5 mm and ⩽10 mm, respectively. The mean postoperative offset difference was 2.39 mm. The investigated LLD and offset results were comparable with literature data of studies utilising an intraoperative measuring device. LLD was significantly decreased when compared to a free-hand technique (LLD 4.42 mm, p < 0.001). Conclusion: The technique utilising preoperative templating, intraoperative offset verification together with the use of hip calibration gauge yielded accurate LLD and offset restoration as in the literature. Precise offset restoration, which often is a neglected issue, can lead to better abductor vector restoration, hip function and less pain.

Background Squeaking is an on-going complication with a variable incidence of 0.5%-20.7%. The mechanism of squeaking has not been understood completely and is most likely multifactorial in nature. Previously, we have reported on a squeaking rate of 7.3% at 2 years. Our current results show a substantial increase in the squeaking incidence from 7.3% to 17.4% with the DeltaMotion articulation at the 5-year follow-up. Methods Two hundred six total hip arthroplasties with a large ceramic-on-ceramic bearing were performed on 195 patients by 2 senior authors. The minimum duration of follow-up was 5 years (range 5-6.2). Results The mean Harris Hip Score remained stable at 91.7 at 5 years compared to 92 after 2 years. However, we observed an increase in the squeaking rate from 7.3% after 2 years to 17.4% after 5 years. As in previous studies, we did not find significant differences between the silent and squeaking group in relation to age, height, weight, and femoral head diameter. In contrast, others reported no significant differences regarding range of motion and gender between the silent and the squeaking hip group at 2 years of follow-up, whereas at 5 years, the squeaking group showed a significantly higher combined range of motion and a higher relative risk of squeaking in women compared to the silent group. Conclusion While large diameter ceramic bearings may produce squeaking, especially in female patients, our mid-term clinical results of a large ceramic-on-ceramic bearing in total hip arthroplasty are encouraging. Nevertheless, long-term follow-up is recommended.

Introduction The technical objective of total knee arthroplasty (TKA) is to restore normal mechanical parameters to the knee. Patient-specific instrumentation (PSI) was developed to streamline the operative process and improve accuracy. PSI produces individualized cutting guides based on three-dimensional models of the patient's anatomy acquired from computed-tomography (CT) or magnetic-resonance imaging (MRI). However, the superiority of one modality over the other remains unclear. Therefore, we aimed to compare the accuracy of patient-specific cutting guides produced from MRI or CT imaging methods in TKA. Methods Electronic databases were systematically searched using relevant keywords and MeSH terms for original-data English-language publications comparing the accuracy of CT and MRI-based PSI cutting guides in TKA. Data was extracted from the text, tables and figures of studies and meta-analysed. Results MRI-based PSI cutting guides produced a lower proportion of coronal plane outliers (>3°) with regard to overall limb mechanical axis (OR 2.75, p = 0.01). There were no significant differences between the two in terms of sagittal femoral and tibial component placement, or coronal femoral and tibial placement, or femoral component axial rotation. Tibial rotation was not analysed in the literature. Conclusions MRI-based patient-specific cutting guides produced a lower proportion of outliers in the overall coronal alignment of the limb compared to CT, with no significant difference between the two in terms of femoral or tibial component placement. Future studies should investigate the differences in resource usage and operative time between the two to inform surgeons' decision making when choosing an ideal imaging modality for PSI TKA. Study design Meta-analysis. Level of evidence III, systematic review of cohort and comparative studies.

Correct component placement is of significant importance to ensure optimal outcomes in total hip arthroplasty (THA). Traditionally, the Lewinnek plane has been referenced as an adequate "safe zone", formed between the anterior superior iliac spines and public tubercles to optimize acetabular orientation. However, recent evidence shows that the positioning of this plane may vary due to the biomechanical relationship between the lumbar spine and hip. Therefore, the plane acquired intraoperatively may not accurately recreate the actual functional plane and acetabular orientation encountered outside of the intraoperative environment. This review summarizes the hip-spine relationship and its implications on THA.

In patient-specifically instrumented (PSI) total knee arthroplasty, the correlation between the pre-operative surgical plan, accuracy of the cutting block, and intra-operative resection size is unclear. The aim of this study was to evaluate the ability to accurately execute the PSI surgical plan and to add to the merging information with respect to this technology with the hypothesis that the PSI blocks would demonstrate good accuracy with regard to the bony thickness of the resections. One hundred and thirty TKAs using PSI (MRI/long-leg radiographs) were retrospectively analysed. All surgeries were conducted via similar surgical approach and technique, with resection performed after guide placement and alignment assessment. The bony cut thicknesses of the medial (MTP) and lateral tibial plateau (LTP), distal medial (DM), distal lateral (DL), posterior medial (PM) and posterior lateral (PL) femur were measured with a vernier calliper. The measured resection thickness was subtracted from the planned resection. Errors were defined as ≤1.5 mm (acceptable), 1.5–2.5 mm (borderline), and >2.5 mm (outliers). Overall, 81 (62.3 %) of the knees were free of outliers. The distal femur cut had the highest proportion of acceptable cut error with 209 of 260 total cuts acceptable (80.4 %). The tibial cuts had the lowest proportion of “acceptable” cuts (68.9 %). Tibial cuts had more outliers (33 of 260 cuts, 12.7 %) than the femur (39 of 520 cuts, 7.5 %) (p = 0.01). Pre-operative varus (n = 97) and valgus (n = 33) deformities demonstrated 7.7 % (45/482) and 13.6 % (27/198) of cuts which were outliers, respectively (p = 0.01). PSI showed only fair to moderate accuracy with 62.3 % of the knees presenting no outliers. The tibia cutting guide was less accurate than the femur. Specific attention is needed when cutting the tibia and in correction of valgus deformity. Moreover, intra-operative verifying measurements can provide feedback to the accuracy of the surgical plan. IV, case series with no comparison group.

Background Venous thromboembolism (VTE) (Deep vein thrombosis (DVT), and pulmonary embolism (PE)), is a common complication in patients undergoing total joint arthroplasty (TJA). Recently, aspirin was recommended by the American Academy of Orthopaedic Surgeons (AAOS) as VTE prophylaxis following TJA. This study investigates VTE rates in TJA patients using as thromboprophylaxis. Methods DVT was screened for in 396 consecutive total hip or knee arthroplasty procedures. Patients were treated with early mobilisation, calf compression device and 300 mg aspirin for 5 days and then 100 mg aspirin for 5 weeks. All patients received lower-limb duplex ultrasonography prior to discharge. Patients were clinically evaluated at 6 weeks post-op documenting any VTE. Results 51 TJA's (12.87%) were complicated by VTE: one proximal, 47 distal DVT and 3 PE. No fatal PE occurred. Only four DVT were symptomatic. Of 159 THA, 2 (1.25%) had VTE: one distal DVT and one PE. Of 237 TKA, 49 (20.67%) had VTE: 1 proximal, 46 distal DVT and 2 PE. Patients with a history of diabetes and those receiving TKA were at higher risk of DVT. Conclusion Multimodal VTE prophylaxis demonstrated a low rate of proximal DVT, PE and bleeding complications. The rate of asymptomatic DVT was high, but most were distal and unlikely to be clinically significant. Patients with diabetes and those receiving TKA could be at higher risk of asymptomatic DVT, and may benefit from closer clinical assessment. These findings suggest aspirin is safe and efficacious when used in combination with mechanical compressors and early mobilisation. However, our findings require further validation, particularly with larger, prospective comparative studies.

Ceramic-on-ceramic (CoC) articulations were developed as an alternative bearing to conventional metal-on-polyethylene (MoP) bearings in order to decrease bearing surface wear and hopefully increase implant longevity. Overall, CoC bearings have the lowest rate of wear among all bearing [1] surfaces and are not associated with complications such as osteolysis and tissue necrosis linked with MoP and metal-on-metal (MoM) articulations, respectively. Despite ceramics’ superior tribological properties, their use has been associated with other complications such as fracture, edge loading, and squeaking. Edge loading and benign squeaking have little clinical significance, while pathological squeaking and fractures are rare. Despite the low rate of clinical complications seen, these factors deter surgeons from routinely using ceramic bearings in total hip arthroplasty (THA). This chapter further expands on these complications.

Metal-on-metal (MoM) bearings for total hip arthroplasty (THA) have come under scrutiny with reports of high failure rates. Clinical outcome studies with several commercially available MoM THA bearings remain unreported. We evaluated 78 consecutive MoM THAs from a single manufacturer in 68 patients. Sixty-six received cobalt–chrome (CoCr) monoblock and 12 received modular titanium acetabular cups with internal CoCr liners. Femoral components were titanium with modular necks. At average 2.1 years postoperatively, 12 THAs (15.4%) demonstrated aseptic failure (10 revisions, 2 revision recommended). All revised hips demonstrated capsular necrosis with positive histology reaction for aseptic lymphocytic vasculitis-associated lesions/adverse local tissue reactions. Prosthetic instability following revision surgery was relatively common. Female gender was a strong risk factor for failure, though smaller cups were not. Both monoblock and modular components fared poorly. Corrosion was frequently observed around the proximal and distal end of the modular femoral necks.

This study compares the incidence of venous thromboembolic event (VTE) in 55 patients (110 knees) undergoing simultaneous bilateral TKA with 287 patients (287 knees) undergoing unilateral TKA using a mobile compression device as monotherapy prophylaxis in both groups. All patients were clinically evaluated 3months after surgery with symptomatic confirmed VTE as an endpoint. Deep venous thrombosis (DVT) was documented by duplex ultrasound and pulmonary embolism (PE) was documented by spiral CT. The simultaneous bilateral TKA group had 6 VTEs (10.9%) with 2 PEs (3.6%). The unilateral TKA group had 9 VTEs (3.1%), and 0 PE. Patients undergoing simultaneous bilateral TKA yielded more than twice the rate of VTE compared with patients undergoing unilateral TKA using a mobile compression device as sole thromboprophylactic modality.

Fresh osteochondral allograft transplantation is an increasingly common treatment option for chondral and osteochondral lesions in the knee, but the long-term outcome is unknown.We determined (1) pain and function, (2) frequency and types of reoperations, (3) survivorship at a median of 13.5 years, and (4) predictors of osteochondral allograft failure in the distal femur.We evaluated 122 patients (129 knees) who underwent osteochondral allograft transplantation of the femoral condyle. Mean age was 33 years and 53% were male. Clinical evaluation included the modified Merle d'Aubigné-Postel (18-point), IKDC, and Knee Society function (KS-F) scores. We defined graft failure as revision osteochondral allografting or conversion to arthroplasty. We determined whether patient characteristics or attributes of the graft influenced failure. Minimum followup was 2.4 years (median, 13.5 years); 91% had more than 10 years of followup.Mean modified Merle d'Aubigné-Postel score improved from 12.1 to 16, mean IKDC pain score from 7.0 to 3.8, mean IKDC function score from 3.4 to 7.2, and mean KS-F score from 65.6 to 82.5. Sixty-one knees (47%) underwent reoperations. Thirty-one knees (24%) failed at a mean of 7.2 years. Survivorship was 82% at 10 years, 74% at 15 years, and 66% at 20 years. Age of more than 30 years at time of surgery and having two or more previous surgeries for the operated knee were associated with allograft failure.Followup of femoral condyle osteochondral allografting demonstrated durable improvement in pain and function, with graft survivorship of 82% at 10 years.

Objectives To determine the histological patterns of posterior cruciate ligament (PCL) degeneration during aging and in relation to changes in articular cartilage and anterior cruciate ligament (ACL) across the entire adult age spectrum. Methods Human knee joints (n=120 from 65 donors) were processed within 72 h of postmortem. Articular cartilage surfaces were graded macroscopically. Each PCL was histologically evaluated for inflammation, mucinous changes, chondroid metaplasia, cystic changes and orientation of collagen fibres. The severity of PCL degeneration was classified as normal, mild, moderate or severe. PCL scores were compared to ACL and cartilage scores from the same knees. Results All knees had intact PCL. Histologically, 6% were normal, 76% showed mild, 12% moderate and 9% severe degeneration. Fibre disorientation was the most prevalent and severe change. Histological grades of PCL and ACL correlated, but significantly fewer PCL than ACL showed severe changes. There was a weaker correlation between aging and total histological PCL scores (R=0.26) compared to aging and ACL scores (R=0.42). ACL scores correlated with cartilage scores (R=0.54) while PCL scores increased with the severity of osteoarthritis from grades 0 to III but not between osteoarthritis grades III–IV (R=0.32). In knees with ruptured ACL, the PCL scores correlated with cartilage scores of the lateral compartment. Conclusions PCL histopathological changes were less severe than in the ACL. PCL degeneration was associated with ACL and cartilage damage. The lack of correlation with age indicates independent pathways for PCL versus ACL degeneration.

Background Venous thromboembolism (VTE) comprises pulmonary embolism and deep vein thrombosis and is a complication of particular concern in lower limb arthroplasty. In recent years, aspirin has emerged as a potential alternative thromboprophylactic agent, particularly after its acceptance as a recommended agent by the American College of Chest Physicians. Aspirin is favorable due to its relative cost-effectiveness and convenience compared to novel oral anticoagulants and warfarin. However, its efficacy since its inclusion in the American College of Chest Physicians guidelines remains unclear. The present systematic review aimed to establish the efficacy of aspirin in preventing VTE in total hip and knee arthroplasty. Methods Electronic searches were performed using 6 databases from up to June 2015, identifying all relevant studies. Data were extracted and meta-analyzed. Results Eleven relevant studies were identified for inclusion in the present meta-analysis. The overall rate of deep vein thrombosis and pulmonary embolism in both hip and knee arthroplasty was 1.2% and 0.6%, respectively. The rate of major bleeding was 0.3%. Pooled mortality rate was 0.2%. All findings demonstrated a high and significant degree of heterogeneity. Conclusion Aspirin, both alone and in multimodal approaches to thromboprophylaxis, confers a low rate of VTE, with a low risk of major bleeding complications. However, the evidence for its use is limited by the low quality of studies and variation in dose in dosing regimes. Future randomized controlled trials should investigate the efficacy of aspirin, as well as the ideal dosing protocol for its use in thromboprophylaxis in arthroplasty.

Median 14-year follow-up (mean 11.8 years) of a cemented primary posterior cruciate-retaining total knee arthroplasty (TKA) utilizing the Press-Fit Condylar (PFC) Sigma design was evaluated in 77 patients (79 TKA). Follow-up assessment included implant survivorship, x-rays, Knee Society rating system, and clinical evaluation. Radiographic analysis demonstrated minor non-progressive osteolysis in 40% (10/25) knees. Two revisions, one for instability at 4 years and one for polyethylene wear at 10 years were performed. Survivorship of the PFC Sigma knee implant was 97% using revision for any reason and 100% using aseptic loosening as endpoints. The PFC Sigma had excellent survivorship at 14 years, the longest clinical follow-up reported.

Injuries to the glenoid labrum are common in young athletic patients and can lead to shoulder pain and instability. Primary repair of glenoid labral tears is more widely performed by arthroscopic reattachment of the detached labrum to the glenoid rim with labral anchor devices.16 While anchors have a large variety in composition, size, and suture configuration, they all utilize the glenoid rim as port of entry into the glenoid vault and the glenoid bone stock as a base for stable attachment. Arthroscopic placement of anchor devices can be challenging because of limited surgical exposure. Understanding the bony morphology of the glenoid and proper arthroscopic placement of the suture anchor are essential to the success of glenoid labral repairs.15 An incorrect angle of insertion can lead to perforation of the glenoid vault or damage to the articular cartilage of the glenoid face, resulting in chronic pain, restriction of motion, recurrence of primary pathology, and reoperation.12 Recent arthroscopic cadaveric studies have shown that the glenoid perforation rate can be as high as 100% during Bankart repair10 and superior labrum anterior to posterior (SLAP) lesion repair.6,13 Medial glenoid cortex perforation during SLAP repair increases the risk of suprascapular nerve injury.6,13,20 Because of scapular anatomy, approaching the posterior glenoid can be clinically challenging. Chan et al2 demonstrated a high perforation rate during SLAP repair. Their cadaveric study showed 14% perforation rate using a low posterosuperior drill hole utilizing the port of Wilmington at the 10:00 clockface position, and 67% of the perforated glenoids demonstrated suprascapular nerve injury. Lehtinen et al9 reported glenoid rim angles at 5 anchor locations, corresponding to the 3:00, 4:30, 6:00, 7:30, and 9:00 clockface positions. We also determined the safe insertion range and optimal insertion angle at the 10:30 position (where the acromion complicates the surgical approach) by simulating the use of the Nevaiser portal and posterolateral to the acromion by simulating the use of the portal of Wilmington. In spite of the reported high glenoid perforation rates and in light of the biomechanical advantage of orthogonal anchor placement relative to the glenoid rim, there are no universally accepted recommendations for surgically safe and optimal insertion angles. The purposes of this study were to (1) determine the safe insertion range available to avoid perforation, (2) determine the optimal insertion angle at various positions on the glenoid rim, and (3) provide surgical guidelines to minimize risk of perforation.

s / Osteoarthritis and Cartilage 20 (2012) S10–S53 S40 61 LONG TERM FOLLOWUP OF FRESH OSTEOCHONDRAL ALLOGRAFTING OF THE FEMORAL CONDYLE Y. Levy , S. Gortz , P. Pulido , J. McCauley , W. Bugbee . 1 Shiley Ctr. for Orthopaedic Res. & Ed. at Scripps Clinic, La Jolla, CA, USA; 2 Tel Aviv Med. Ctr., Div. of Orthopaedic Surgery, Tel Aviv, Israel; Univ. of California, San Diego Med. Ctr., san diego, CA, USA; 4 Scripps Clinic, Div. of Orthopaedic Surgery, La Jolla, CA, USA Background and purpuse: Articular cartilage injuries of the distal femur are a challenging clinical entity. Fresh osteochondral allografting (OCA) is an increasingly popular option for articular cartilage restoration. Many short-term follow up studies demonstrate promising clinical results, but there are few long-term follow up studies that provide information about graft survivorship and durability. The purpose of this study was to assess long-term clinical outcome, determine frequency and types of reoperations, determine survivorship, and to evaluate predictors of OCA failure in patientsundergoing freshOCAtransplantationdue tovariouspathologies. Methods: Since 1983, our IRB-approved OCA outcomes program has collected data on 614 OCA transplantation procedures of the knee performed in 536 patients. Of those, we evaluated 122 patients (129 knees) who underwent OCA transplantation of the femoral condyle, were at least ten years out from the index surgery and had a minimum two-year followup. Mean age was 31.7 years (range, 1568 years); 85% were younger than 45 years. 53% were male 47% were female. Diagnoses included osteochondritis dissecans (45%), traumatic cartilage injury (22.5%), degenerative chondral lesion (15.5%), avascular necrosis (14.7%), and osteochondral fracture (2.3%). Average total graft area was 8.1 cm2 (range, 0.7-28.5 cm2). Clinical evaluation included the modified D'Aubigne and Postel (18-point) scale, International Knee Documentation Committee (IKDC) pain and function scores, Knee Society (KS) function scores and measures of subjective satisfaction. Reoperations and failures were recorded. Graft failure was defined as revision OCA, or conversion to arthroplasty. Results: Mean followup was 14.2 years (range, 2-27.5 years). Mean 18point score improved from 12.1 to 16.0, mean IKDC pain score improved from 7.0 to 3.8, mean IKDC function score from 3.4 to 7.2, andmean KS-F score from 65.6 to 82.5 (all, p