Introduction: The minimally invasive approach using the Oxford Unicompartmental Knee Replacement (UKR) in medial compartment osteoarthritis has gained significant popularity. A number of advantages have been attributed both to UKR and minimal invasive surgery in unilateral replacement.We have therefore evaluated the outcomes of simultaneous bilateral UKR at our institution and report a unique way of safely positioning these patients.

Method: Twenty patients were assessed undergoing bilateral UKR from 2001 to 2003. The study cohort included 11 females and 9 males with a mean age of 66 years. A matched cohort group undergoing simultaneous bilateral Total Knee Replacement (TKR) of 15 patients was evaluated as a control group. Peri -operative and later post- operative data was collected during hospitalisation or at standard outpatient follow -up. We will also demonstrate our unique patient positioning for bilateral UKR.

Results: No significant difference was shown regarding mean tourniquet times (97.8 min in bilateral UKR, 92.1 min in bilateral TKR) and mean Haemoglobin drop (2.15 gdl with bilateral UKR, 2.82 gdl with bilateral TKR). We note a significant benefit in mean blood product requirement between the bilateral unicompartmental (0 units) and total knee groups (3 units). Incidence of peri-operative complications was higher in the total knee group (4 in bilateral TKR, none in the bilateral UKR group). No complication required surgery. There was a reduced mean hospital stay of 6 days in bilateral UKR compared with 9.3 days in bilateral TKR. With regard to late complications, each group had one complication, of stiffness. Radiographic evaluation at a mean 9 months showed 4of 30 UKR to have minimal malposition, with no clinical correlation.Patient satisfaction was evaluated using the Oxford Knee Score, showing 12 patients (80%) obtained excellent or good results and 3 patients (20%) scoring a moderate or poor result. The patients in the moderate and poor groups all complained of unilateral stiffness.

Conclusion: It is possible to safely undertake bilateral simultaneous Oxford unicompartmental knee replacements using a minimally invasive technique using our described method of positioning, with good results for patients with symmetrical medial compartment knee arthritis.We note improved post-operative morbidity, physiological derangement and length of stay in our patients as compared to an age,sex,co morbidity-matched cohort of bilateral TKR patients

We assessed hyperextension of the knee and joint laxity in 169 consecutive patients who underwent an anterior cruciate ligament reconstruction between 2000 and 2002 and correlated this with a selected number of age- and gender-matched controls. In addition, the mechanism of injury in the majority of patients was documented. Joint laxity was present in 42.6% (72 of 169) of the patients and hyperextension of the knee in 78.7% (133 of 169). All patients with joint laxity had hyperextension of their knee. In the control group only 21.5% (14 of 65) had joint laxity and 37% (24 of 65) had hyperextension of the knee. Statistical analysis showed a significant correlation for these associations. We conclude that anterior cruciate ligament injury is more common in those with joint laxity and particularly so for those with hyperextension of the knee.

Purpose of the study A prospective observational study to ascertain any correlation between joint laxity and knee hyperextension to anterior cruciate ligament rupture.

Methods used Joint laxity as defined by Beighton’s method and hyperextension of uninjured knee in 169 patients with symptomatic isolated anterior cruciate ligament rupture was recorded in a prospective fashion. This was correlated to the scores obtained in a selected group of age and sex matched controls

Results 72 out of 169 of the patients had hyperlaxity in their joints and 133 out of 169 had knee hyperextension. In the control group 14 out of 65 had hyperlaxity in their joints and 24 out of 65 had knee hyperextension.

Statistical analysis showed that ACL injury was common in those with lax joints and with knee hyperextension with a p < 0.001

Conclusion ACL injury is common in patients with joint laxity especially in those with knee hyperextension.