Combined quadriceps medial patellofemoral ligament reconstruction and osteochondral fixation offers good patient-reported outcomes and low rates of recurrent instability for osteochondral defects secondary to acute patella dislocation.

PURPOSE: Chondral injuries secondary to traumatic patella dislocation are common, and a subgroup of these are significant defects with fragments amenable to fixation. There is a paucity of published evidence assessing patients managed with combined acute patellofemoral stabilisation and osteochondral fixation. The purpose of this study is to report the outcomes of patients with osteochondral injuries secondary to acute traumatic patella dislocation treated with combined early fragment fixation and MPFL reconstruction using a quadriceps tendon turndown technique which has distinct advantages for this cohort, including preventing chondral overloading and non-violation of the patella bone. METHODS: Patients who underwent combined quadriceps tendon MPFL reconstruction and osteochondral fixation were included. Patient demographics, defect characteristics, complications and reoperations were evaluated. Patients were assessed with Lysholm, Kujala, KOOS-PF scores and satisfaction scale at follow up. Pre-operative MRI was assessed for presence of radiological risk factors for patella dislocation and post-operative MRI was used to assess cartilage quality with MOCART 2.0 score. RESULTS: A total of 19 patients (63.2% female) were included. The mean age was 17.4 ± 4.8 years and patients were followed up at a mean 15.8 ± 5.1 months post-surgery. The mean defect size was 2.4 cm2 ± 1.3 cm2, with the most common defect location being the patella (13/19; 68.4%) followed by the lateral femoral condyle (5/19; 26.3%). At final follow up, the overall mean Lysholm, Kujala, and KOOS-PF scores were 84.9 ± 11.1, 89.7 ± 5.8 and 80.6 ± 13.6, respectively. Seventeen patients (89.5%) were satisfied with their outcome. The mean MOCART 2.0 score at final follow-up was 72.5. One patient required medial capsular plication with removal of a loose chondral body and microfracture and 3 knees required minor reoperations. CONCLUSION: Combined acute osteochondral fragment fixation and MPFL reconstruction using a quadriceps tendon graft offers good radiological and patient-reported outcomes with high satisfaction and low rates of recurrent patella dislocation. To our knowledge, this is currently the largest series of its kind in the literature and the results of this study provide a rationale for a combined approach using a quadriceps tendon graft for this cohort. LEVEL OF EVIDENCE: Level IV.

Magnetic resonance imaging features of preserved vs divided and repaired piriformis during total hip arthroplasty: a randomized controlled trial.

The aim of this study was to compare the muscle grade and bulk of the divided and repaired piriformis tendon by the standard posterior approach with the preserved tendon by a piriformis-sparing (PS) approach, in total hip arthroplasty. Twenty-two patients were randomized to either approach. Patients received preoperative and 3 months and 2 years postoperative magnetic resonance imaging scans. Patients and evaluators were blinded to allocation. There was significantly less deterioration in piriformis muscle grade (P = .029) and bulk (P = .015) in the PS group at 3 months. At 2 years, only the difference in grade remained significant (P = .001). There was no difference in Oxford hip scores. In conclusion, a PS approach avoids the marked wasting and deterioration in muscle grade that occurs postoperatively in the standard posterior approach.

Osteochondral Shearing Fracture of the Humeral Head Associated with Traumatic Anterior Shoulder Dislocation: A Case Report.

CASE: Osteochondral shearing fracture of the humeral head after an anterior shoulder dislocation is a condition that has rarely been reported in literature. We report a case of a large posteriorly located fragment of such a fracture in a 23-year-old man. We performed open reduction and internal fixation with resorbable pins through a deltopectoral approach and subscapularis tenotomy. CONCLUSION: In our case of a large osteochondral fracture of the posterior humeral head, treatment by open reduction and internal fixation showed an excellent radiographic result at 1 year and clinical result up to 5 years postoperatively.

Cement penetration after patella venting.

There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement.

Catastrophic failure of 4 cobalt-alloy Omnifit hip arthroplasty femoral components.

BACKGROUND: Femoral component neck fracture is an uncommon type of failure in total hip arthroplasty. We present a report on 4 retrieved cobalt-chrome femoral components that fractured at the neck, where we investigated the mechanisms of failure. METHODS: The 4 retrieved implants were analyzed with regard to their macro- and microstructures and the fracture surfaces were examined using electron microscopy. The medical record of each patient was also examined for any history of complications prior to failure of the implant. RESULTS: These fractures occurred immediately adjacent to the base of the modular head. Skirted modular heads were used in 3 of the 4 failed components. This constructs promotes corrosion. Cyclic fatigue-loading in combination with the material factors of course grain microstructure and extensive carbide precipitation along the grain boundaries were also identified as the cause of implant failure. INTERPRETATION: Our findings suggest that a solution annealing step could be introduced into the manufacturing process to improve the microstructure of the cobalt chrome alloy. We also advise caution in using a skirted modular head in combination with a device of known suboptimum microstructure, for a greater margin of safety.

Varus/valgus alignment of the femoral component in total knee arthroplasty.

The position of the femoral component in 362 total knee replacements was assessed radiologically. A subgroup of 32 knees, 18 of which had perfect alignment and 14 with imperfect alignment underwent CT scout scans of the femur from which the mechanical axis of the femur could be measured. Radiologically 92% of all components were implanted within 3 degrees of the target value. There was close correlation between the CT and X-ray measurements in the subgroup. Deviation from the mechanical axis was 1.16 degrees (range -2.5 to +2) in the perfectly aligned knees, validating both surgical technique and radiological assessment. Causes for inaccuracy in femoral placement and future likely developments are discussed.

Fixed flexion deformity and flexion after knee arthroplasty. What happens in the first 12 months after surgery and can a poor outcome be predicted?

Fixed flexion deformity and flexion of 284 knee replacements were recorded pre-operatively at 6 weeks and 12 months after surgery. Eighteen knees (6.3%) achieved unsatisfactory movements at 12 months. Seven knees (2.4%) had a fixed flexion greater than 10 degrees, six (2.1%) had flexion less than 90 degrees and five (1.8%) had both. The only pre-operative variable of predictive value for a poor outcome was a high fixed flexion deformity (10 out of 52 knees P<0.001). Only one out of 15 knees with limited pre-operative flexion was restricted afterwards. Seven knees (2.4%) with good pre-operative movements developed either limited flexion or a fixed flexion greater than 10 degrees, none had both. There were no post-operative events which contributed to this. Eight knees (2.8%) achieved very poor movements. In each case there was a significant post-operative event which contributed to this. Overall, the flexion achieved at 12 months was directly related to the pre-operative flexion. Those knees with <90 degrees of flexion gained 29.3 degrees (S.D. 18). Those with 130 degrees or greater flexion lost 15.2 degrees (S.D. 13.6). The mean pre-operative fixed flexion was reduced by 50% at 6 weeks and again at 12 months. Knees with a high fixed flexion deformity alone pre-operatively have an increased risk of developing stiffness afterwards even if the deformity is corrected at surgery. In most cases significant post-operative events play a major role in this outcome. A small percentage of knees develop stiffness without any obvious explanation.