The Medial Patellofemoral Ligament (MPFL) is the main restraining force against lateral patellar displacement. It is often disrupted following patellar subluxation or dislocation. MPFL reconstruction is frequently performed when conservative management fails and the patient experiences recurrent patellar dislocation. Various MPFL reconstruction procedures have been described in the literature and reported outcomes are encouraging. This study analyses the radiographic outcomes following MPFL reconstruction. From January 2006 to January 2011, 76 consecutive patients (80 knees) with patellar recurrent dislocation underwent medial patellofemoral ligament reconstruction in three large teaching hospitals. Mean follow-up was 31.8 months (range, 13–72). Semitendinosus and gracilis autografts were used for the reconstruction and all procedures were carried out by the senior authors (WL, BR, CW, MB). Plain radiographs (Anteroposterior (AP), Lateral and Skyline) performed preoperatively and postoperatively were used to compare the sulcus angle, congruence angle, lateral patellofemoral angle, trochlear dysplasia (Dejour classification), trochlear boss height and patellar height (Caton-Deschamps ratio). Plain radiographs (Lateral) performed postoperatively were used to evaluate the femoral tunnel placement used for MPFL reconstruction. The sulcus angle improved from 143.2° (122.9–157.7) to 139.3° (115.7–154.6) and the congruence angle improved from 26.7° (−17.5–82.6) to 0.26° (−35.3–7.8). The lateral patellofemoral angle was 7.99° (3.2–19.2) preoperatively and 9.02° (3.2–18.2) postoperatively. The Caton-Deschamps ratio was 1.2 (1.0–1.5) preoperatively and 1.0 (0.8–1.1) postoperatively. Using the Dejour classification of trochlear dysplasia, all preoperative radiographs were considered to be grade C or D and all postoperative radiographs were considered to be grade A or B. Trochlear boss height was 5.9mm (1.8–11.6) preoperatively and 4.7mm (1.6–6.9) postoperatively. 59% of the femoral tunnels were considered to be in a good position on postoperative radiographs. This study displayed a significant improvement in postoperative radiographic parameters, demonstrating the importance of anatomic restoration when performing MPFL reconstruction.
We report the short term follow up of nineteen consecutive PFC sigma unicompartmental knee replacements carried out in our institution with minimum one year follow up. The PFC Sigma medial unicompartmental knee replacement is a fixed bearing, cemented unicompartmenal knee replacement. There are currently no published reports of follow up for the PFC Sigma medial unicompartmental knee replacement. Nineteen patients (nineteen knees) underwent PFC sigma medial unicompartmental knee arthroplasty. The pre-operative diagnosis was osteoarthritis in eighteen patients and osteonecrosis in one patient. There were ten males and nine females with a mean age of sixty four years. All patients had clinical and radiological review at one year. All operations were carried out by the two senior authors (BPR and BL). The mean length of admission was 2.7 days (Range 2–5). There have been no infective or thromboembolic complications to date. The mean oxford scores improved from 41 (Range 26–52) pre-operatively to 18 (15–27) at one year follow-up. The mean range of motion improved from 115 degrees of flexion preoperatively to 125 degrees. All radiographs were satisfactory at one year follow up with no evidence of loosening. We report the promising early results of a new medial unicompartmental knee replacement with at least one year follow up. No early complications or infections were identified in our cohort of patients.
The objective was to seek evidence of hypoxia in early human tendinopathy and thereafter, to explore mechanisms whereby tissue hypoxia may regulate apoptosis, inflammatory mediators and matrix regulation in human tenocytes. Fifteen torn supraspinatus tendon (established pathology) and matched intact subscapularis tendon (representing ‘early pathology’) biopsies were collected from patients undergoing arthroscopic shoulder surgery. Control samples of subscapularis tendon were collected from 10 patients undergoing arthroscopic stabilisation surgery. Markers of hypoxia were quantified by immunohistochemical methods. Human tendon-derived primary cells were derived from hamstring tendon tissue obtained during hamstring tendon ACL reconstruction. The impact of hypoxia upon tenocyte biology Increased expression of HIF 1a, Bcl-2 and clusterin (hypoxic and apoptotic markers) was detected in subscapularis tendon samples compared to both matched torn samples and non matched control samples (p<0.01). Hypoxic tenocytes exhibited increased production of proinflammatory cytokines (p<0.001), altered matrix regulation (p<0.01) with increased production of Collagen type III operating through a MAPK dependent pathway. Finally, hypoxia increased expression of several mediators of apoptosis and thereby promoted tenocyte apoptosis. Hypoxia promotes expression of proinflammatory cytokines, key apoptotic mediators and drives matrix component synthesis towards a collagen type III profile by human tenocytes. We propose hypoxic cell injury as a critical pathophysiological mechanism in early tendinopathy offering novel therapeutic opportunities in the management of tendon disorders.
We aim to compare post-operative length of stay and cardiopulmonary morbidity in patients randomised to either navigated or conventional total knee arthroplasty (TKA). Patients undergoing primary TKA for osteoarthritis were prospectively assigned randomly to either navigation-guided or control groups and blinded to this. All patients received a PFC implant (DePuy, Warsaw, IN). In the control group the standard femoral intramedullary and tibial extramedullary alignment rod was used. In the navigation group, the BrainLab (Munich, Germany) navigation system was used. All operations were carried out by one of two consultant orthopaedic knee surgeons. Length of post operative hospital stay and the development of cardiopulmonary complication were recorded and groups compared. 100 patients were recruited (55 control vs 45 navigated). Patient demographics were similar in both groups. Mean length of stay was 7 days in the control group (range 3-101), 5 days in the navigation group (range 3-10). The mode was 4 days in both groups. 7 patients (13%) stayed for >7 days in the control group, 3 patients (7%) stayed >7 days in the navigation group(p=0.339). 4 patients(7%) required >10 days inpatient stay in the control group, 0 patients required to stay in hospital for longer than 10 days in the navigation group(p=0.069). The causes for the length of stay exceeding 10 days were pulmonary embolus in 3 patients, and chest infection in 1 patient. Patients undergoing navigation-guided TKA required shorter post-operative inpatient stays than those undergoing arthroplasty using conventional techniques. Fewer patients in the navigation group required stays longer than 7 or 10 days. The difference in post-operative stay was associated with fewer respiratory complications in the navigated group.
The medial patellofemoral ligament is commonly torn in first patella dislocation and according to the literature occurs most frequently at the femoral insertion. As research has demonstrated the MPFL to be a primary soft tissue stabilizer of the patella there has been increased interest in acute repair of the ligament with the aim of reducing the risk of recurrent dislocation. MRI is generally used pre op to identify the site of rupture allowing planning of the surgical repair, however there is currently no published data regarding the correlation between surgical and MRI findings to confirm the reliability of this modality of imaging. A retrospective analysis of all patients who were referred for MRI following patella dislocation was performed. The surgical and MRI findings of those who subsequently underwent MPFL repair were compared to look for any correlation. 41 patients were first time patella dislocators and 38 had MPFL rupture diagnosed on MRI. Of these 19 progressed to surgical intervention and 17 had adequate data available from the notes and to permit comparison. All of the MPFLs ruptured at the patella insertion. In 76.5% (13/17) of patients the site of MPFL rupture was correctly identified on MRI scan. Of those that were discordant 3/4 had the site of rupture identified as the femoral insertion on MRI and on 1/4 the MRI suggested rupture at both the femoral and patella insertions. MPFL rupture is common in first time dislocations occurring in 93%% of this cohort. There was a clear predominance patella insertion rupture in our study which contrasts with the majority of the published literature. By correlating surgical and radiological findings we can conclude that while MRI can accurately diagnose MPFL rupture at the patella insertion but it is less accurate in identifying rupture at the femoral insertion.
