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.
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. A dataset of 160 consecutive THAs performed by a single surgeon was included. 103 were performed with computer navigation and 57 were non navigated. We calculated limb length discrepancy from pre and post op radiographs. We retrieved the intra-operative computer generated limb length alteration data pertaining to the navigated group. We used independent sample t test and descriptive statistics to analyse the data.INTRODUCTION
METHODS
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 211 TKAs performed by a single surgeon using a medial approach. 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 linear model was used to predict change in maximum extension from pre- to post-implant. 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 (r2adj=0.170). This model predicted that carrying out a TKA with 19 mm bone cuts, 10 mm insert and no soft tissue release would give 4.2° increase in extension. It predicted that a moderate release would give a further 2.8° increase in extension with an extensive release giving 3.9°. For each mm increase in bone cuts the model predicted an 0.8° increase in extension and for each mm increase in insert size a decrease extension by 1.1°. 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 4–5 mm. However this model only accounted for 17% of the variation in change in extension pre- to post-implant so may not be accurate at predicting outcomes for specific patients.
Aseptic loosening is the most common mode of failure of massive endoprostheses. Introduction of Hydroxyapatite coated collars have reduced the incidence of aseptic loosening. However bone growth is not always seen on these collars. The aims of our study were to determine the extent of osseous integration of Hydroxyapatite coated collars, attempt a grading system for bone growth and to determine the effect of diagnosis, surgical technique and adjuvant therapy on bone growth.Introduction
Objectives
We aimed to determine the extent of osseous integration of the hydroxyapatite collars of tumour endoprostheses implanted in our unit. We identified 57 patients who had massive endoprostheses implanted over the last six years and reviewed clinical records and x-rays. There were 20 proximal femoral, 23 distal femoral, 6 proximal tibial, 8 proximal humeral and 1 distal humeral replacements. Patients fell into three groups: 1.Primary bone tumours, 2. Metastatic bone tumours and 3. Non-tumour indicationsIntroduction
Methods
The aim of this prospective study was to determine the usefulness of a gravity stress view in detecting instability in isolated Weber B fractures of the fibula. We used a standard protocol for patient selection, exclusion, surgery/conservative management and follow-up. Open fractures, fracture dislocations, those with medial/posterior malleolus fractures and those with preliminary X-rays showing a talar shift/tilt were excluded. If the medial clear space increased beyond 4mm on stress radiographs, surgical reduction and fixation of the lateral malleolus was performed. If this remained 4mm or less conservative treatment was undertaken. We followed these patients at 2, 4, 6 and 12 weekly intervals.Purpose
Materials and methods
Percutaneous fixation is a well recognised technique in the treatment of three-part and four-part fractures of the proximal humerus. Minimal fixation of these fractures do show good functional outcome and may further reduce the incidence of avascular complications. We report a preliminary series of 11 patients who underwent percutaneous minimal fixation of such complex humeral fractures using a new technique. 11 consecutive patients (7 with three-part fractures and 4 with four-part fractures) treated by percutaneous limited fixation in our Hospital were involved in this retrospective study. There were 7 fractures with valgus displacement. Percutaneous technique was employed using small incisions and the fracture was reduced under image guidance. The three-part and the four-part fractures were essentially converted into two part fractures, i.e. only the greater and the lesser tuberosities were re-attached to head with AO cancellous screws after realignment of the fragments. The shaft of the humerus was not fixed to the head in any of the cases. All of these cases had a minimum follow-up of at least 6 months. The results were evaluated using the Constant -Murley Shoulder score. 1 out of 11 cases had to be converted to hemi-arthroplasty due to secondary redisplacement of the fracture. The remaining 10 cases showed good bony union although the greater tuberosity in 2 cases showed a residual superior displacement of 3mm and a residual valgus displacement in 2 out of 7 cases. There were no complications of avascular necrosis in any of the cases. Clinically, compared to the uninjured side the average constant score was 93.7% (range- 68.7% – 100%). 7 patients were very satisfied and 4 were satisfied with the operation. Percutaneous minimal fixation achieves good to very good functional outcome comparable to the conventional methods and theoretically reduces the incidence of infection, avascular necrosis and neurological complications.