In arthritic knees with severe valgus deformity Total Knee Arthroplasty (TKA) can be performed through medial or lateral parapatellar approaches. Many orthopaedic surgeons are apprehensive of using the lateral parapatellar approach due to lack of familiarity and concerns about complications related to soft tissue coverage and vascularity of the patella and the overlying skin. However surgeons who use this approach report good outcomes and no added complications. The purpose of our study was to compare outcomes following TKA performed through a medial parapatellar approach with those performed through a lateral parapatellar approach in arthritic knees with severe valgus deformity.

We conducted a retrospective review of patients from two consultants using computer navigation for all their TKAs. All patients with severe valgus deformities (Ranawat 2 & 3 grades) operated on between January 2005 and December 2011 were included. 66 patients with 67 TKAs fulfilled the inclusion criteria. Patients were group by approach; Medial = 34TKAs (34 patients) or Lateral = 33 TKAs (32 patients). Details were collected from patients' records, AP hip-knee-ankle (HKA) radiographs and computer navigation files. Outcome measures included lateral release rates, post-operative range of knee movements, long leg mechanical alignment measurements, post-operative Oxford scores at six weeks and one year, patient satisfaction and any complications. Comparisons were made between groups using t-tests.

The total cohort had a mean age of 69 years [42–82] and mean BMI of 29 [19–46]. The two groups had comparable pre-operative Oxford scores (Medial 41[27–56], Lateral 44 [31–60]) and pre-operative valgus deformity measured on HKA radiographs (Medial 13° [10°–27.6°], Lateral 12° [6°–22°]). Three patients in the Medial group underwent intra-operative lateral patellar release to improve patellar tracking. Seven patients in the Lateral group had a lateral condyle osteotomy for soft tissue balancing (one bilateral). There was no statistically significant difference between groups at one year follow up for maximum flexion (Medial 100° [78°–122°], Lateral 100° [85°–125°], p=0.42), fixed flexion deformity (Medial 1.2° [0°–10°], Lateral 0.9° [0°–10°], p=0.31) or Oxford score (Medial 23 [12–37], Lateral 23 [16–41], p=0.49). Similarly there was no difference in the patient satisfaction rates between the two groups at one year follow up. However there was a statistically significant difference in the mean radiographic post-operative alignment angle measurement (Medial 1.8° valgus [4° varus to 10° valgus], Lateral 0.3° valgus [5° varus to 7° valgus], p=0.02). One patient in the Medial group had a revision to hinged knee prosthesis for post-operative instability. There was no wound breakdown or patellar avascular necrosis noted in either of the groups.

The lateral parapatellar approach resulted in slightly better valgus correction on radiographs taken six weeks post-operatively. We found no major complications in the Lateral parapatellar approach group. Specifically we did not encounter any difficulties in closing the deep soft tissue envelope around the knee and there were no cases of patellar avascular necrosis or skin necrosis. Hence we conclude that lateral parapatellar approach is a safe and reliable alternative to the medial parapatellar approach for correction of severe valgus deformity in TKA.

INTRODUCTION

Leg length discrepancy following total hip arthroplasty (THA) can be functionally disabling for affected patients and can lead on to litigation issues. Assessment of limb length discrepancy during THA using traditional methods has been shown to produce inconsistent results. The aim of our study was to compare the accuracy of navigated vs. non navigated techniques in limb length restoration in THA.

Distal femur resection for correction of flexion contractures in total knee arthroplasty (TKA) can lead to joint line elevation, abnormal knee kinematics and patellofemoral problems. The aim of this retrospective study was to establish the contribution of soft tissue releases and bony cuts in the change in maximum knee extension in TKA.

Data were available for 209 navigated TKAs performed by a single surgeon using a medial approach. All patients had the same cemented implant, either CR or PS, which both required a minimum thickness of 10 mm for the tibial and 9mm for the femoral component. Intra-operatively pre- and post-implant extension angles and the size of bone resection were collected using a commercial navigation system. The thickness of polyethylene insert and the extent of soft tissue release performed (no release, moderate and extensive release) were collected from the patient record. A univariate linear regression model was used to predict change in maximum extension from pre- to post-implant.

The mean bone resection was 19mm (15 to 28 mm) (Figure 1).79% of polyethylene inserts were 10mm thick (10 to 16 mm). 71% of knees had no soft tissue release. The mean increase in extension was 5° (11° decrease to 23° increase) (Figure 1). The analysis showed that bone cuts (p<0.001), soft tissue release (p=0.001) and insert thickness (p=0.010) were all significant terms in the model (r²_adj=0.170). This model predicted that carrying out a TKA with 19mm bone cuts, 10mm insert and no soft tissue release would give 4.2° increase in extension. It predicted that a moderate release would give a 2.8° increase in extension compared to no release, with an extensive release giving 3.9° increase over no release. For each mm increase in bone cuts the model predicted a 0.8° increase in extension and for each mm increase in insert size a decrease extension by 1.1°.

Preoperative FFC contracture is a frequent condition in TKA that the surgeon has to address either by resecting more bone or by extending soft tissue release to increase the extension gap to fit the knee implant. This analysis of 209 navigated knee arthroplasty showed that both options are suitable to increase the extension gap. The modelling results show that in general to increase maximum extension by the same as an extensive soft tissue release that bone cuts would have to be increased by 4–5mm. However this model only accounted for 17% of the variation in change in extension pre- to post-implant so is poor at predicting outcomes for specific patients. The large variation in actual FFC correction indicates that this relies on factors other than bone cuts and soft tissue releases as quantified in this study.

This study sought to determine if treatment of resistant clubfeet by the Ilizarov method influenced the pattern of recurrence. Forty-seven children were identified as having undergone treatment by the Ilizarov method. Inclusion criteria for treatment with the Ilizarov method were clubfeet belonging to diagnostic categories that had recognised tendencies for resistance to standard methods of clubfoot management or a previous history of soft tissue releases performed adequately but accompanied by rapid relapse.

There were 60 feet with a mean follow-up of 133 months (46-224). Diagnoses included 34 idiopathic types, 7 arthrogryposis, 1 cerebral palsy, and 5 other. Summary statistics and survival analysis was used; failure was deemed as a recurrence of fixed deformity necessitating further correction. This definition parallels clinical practice where attainment of ‘normal’ feet in this group remains elusive, and mild to moderate relapses that remain passively correctable are kept under observation.

Soft tissue releases were common primary or secondary procedures. The mean time to revision surgery, if a soft tissue release was undertaken as a primary procedure, was 36 months (SD 22), and 39 (SD 23) months if undertaken for the second time. This compares with 52 months (SD 32) if Ilizarov surgery was used. Using survival analysis, there is a 50% chance of a relapse sufficiently marked to need corrective surgery after 44 months following the first soft tissue release, 47 months if after the second soft tissue procedure and 120 months after the Ilizarov technique.

We conclude that resistant club feet, defined as those belonging to diagnostic categories with known poor prognoses or those that succumb to an early relapse despite adequate soft tissue surgery, may have longer relapse-free intervals if treated by the Ilizarov method.

Aim

The aim of this study was to compare the results of humerus intramedullary nail (IMN) and dynamic compression plate (DCP) for the management of diaphyseal fractures of humerus.