Background

Bone preservation is desired for future revision in any knee arthroplasty. There is no study comparing the difference in the amount of bone resection when soft tissue balance is performed with or without computer navigation.

To determine the effect on bony cuts when soft tissue balance is performed with or without use of computer software by standard manual technique in total knee arthroplasty.

One hundred patients aged 50 to 88 years underwent navigated TKR for primary osteoarthritis. In group A, 50 patients had both soft tissue release and bone cuts done using computer-assisted navigation. In group B, 50 patients had soft tissue release by standard manual technique first and then bone cuts were guided by computer-assisted navigation.

In group A the mean medial tibial resection was 5 ± 2.3 mm and lateral was 8 ± 1 mm compared to 5 ± 2 mm (P = 0.100) and 8 ± 1 mm respectively in group B (P = 0.860). In group A the mean medial femoral bone cut was 9 ± 2.9 mm and lateral was 8 ± 2 mm as compared to 9.5 ± 2.9 mm (P = 0.316) and 10 ± 2.2 mm respectively in group B (P = 0.001). Average prosthesis size was 6 (range 3 to 8) in group A as compared to size 5 (range 2 to 7) in group B. Average navigation time in group A was 102 minutes (range 45 to 172) and in group B was 83 minutes (range 42 to 165, P = 0.031).

Our results show that performing soft tissue release and bone cuts using computer- assisted navigation is more bone conserving as compared to manual soft tissue release and bone cuts using computer navigation for TKR, thus preserving bone for possible future revision surgery.

Aim

To determine if the location and pattern of knee pain as described by the patients using the knee pain map was comparable with the intra articular pathology found on arthroscopy as well as to facilitate diagnosis based on pain.

Background: Intraarticular loose bodies following simple dislocations can lead to early degeneration. Non concentric reduction may indicate retained loose bodies and offer a method to identify patients requiring exploration to avoid this undesirable outcome.

Methods: 117 consecutive simple dislocations of the hip presenting to the hospital from January 2000 to June 2006 were assessed for congruency after reduction by fluoroscopy and good quality radiographs. Patients with non concentric reduction underwent open exploration to identify the etiology and removal of loose bodies. The post operative results were analyzed using Thomson and Epstein clinical and radiological criteria.

Results: 12 of the 117 (10%) dislocations had incongruent reduction which was identified by a break in Shenton’s line and an increase in medial joint space in seven patients, superior joint space in three patients or a concentric increase in two patients. CT scan performed identified the origin of the osteocartilagenous fragment to be from the acetabulum in six patients, femoral head in four, from both in one and one patient had inverted posterior labrum. In addition to this a patient had posterior capsular interposition. Following debridement, congruent reduction was achieved in all patients. At an average follow up of four years and nine months (4.9 years), the functional outcome evaluated by Thompson and Epstein criteria was excellent in 11 cases and good in one case.

Conclusions: Intra articular loose bodies were identified by non-concentric reduction in 12 out of 117 patients with simple hip dislocation. Careful evaluation by immediate post reduction fluoroscopy and good quality radiographs are a must following reduction of hip dislocations.