Abstract

Background

Alignment and soft tissue (ligament) balance are two variables that are under the control of a surgeon during replacement arthroplasty of the knee. Mobile bearing medial unicompartmental knee replacements have traditionally advocated sizing the prosthesis based on soft tissue balance while accepting the natural alignment of the knee, while fixed bearing prosthesis have tended to correct alignment to a pre planned value, while meticulously avoiding overcorrection. The dynamic loading parameters like peak adduction moment (PKAM) and angular adduction Impulse (Add Imp) have been studied extensively as proxies for medial compartment loading. In this investigation we tried to answer the question whether correcting static alignment, which is the only alignment variable under the control of the surgeon actually translates into improvement in dynamic loading during gait. We investigated the effect of correction of static alignment parameter Hip Knee Ankle (HKA) angle and dynamic alignment parameter in coronal plane, Mean Adduction angle (MAA) on 1st Peak Knee Adduction Moment (PKAM) and Angular Adduction Impulse (Add Imp) following medial unicompartmental knee replacements.

Ruptures of the patellar and/or quadriceps tendon are rare injuries requiring immediate repair to re-establish knee extensor continuity and to allow early motion. Ultrasound is extensively used as a diagnostic tool before surgery on acute traumatic tears of the patellar tendon and quadriceps tendons.

Our aim was to re-evaluate the value/role of sonography in diagnosing quadriceps and patellar tendon rupture and in differentiating partial from complete tears. To correlate the intra operative findings with the ultrasound report.

A retrospective review of 32 consecutive patients who had a surgical intervention for suspected acute quadriceps and patellar tendon rupture over the last 3 years. Intra-operative findings, clinical, x-ray, ultrasound and MRI reports were correlated.

Seventeen patients had a suspected patellar tendon rupture on clinical examination and 15 patients had suspected quadriceps tendon rupture. Diagnosis was confirmed by clinical examination and x-rays alone in 9 patients, with additional ultrasound in 18 patients and with MRI scan in 5 patients. There were 6 false positives out of 18 [33.3%] in the ultrasound proven group and 1 false positive out of 9 [11.1%] in the clinical examination and x-ray only group. MRI was 100% accurate [n=5].

This is a small, but important study. Ultrasound offers a low degree of sensitivity and specificity in diagnosing acute quadriceps and patellar tendon ruptures. As a result, patients are being exposed to the risks of surgery unnecessarily. We recommend MRI scan as a first line of investigation in patients where the diagnosis is clinically ambiguous. Ultrasound assessment should not be relied upon in when making the decision to operate.

Introduction/Aims: Early results of a prospective randomised control trial suggested improved position of components implanted during primary hip replacement. The aim of this study is to definitively show the benefit of computer aided navigation in hip arthroplasty with regard to acetabular component position, stem position and leg length.

Method: Eighty consecutive patients were prospectively recruited. Patients were quasi-randomised, on an alternating basis, to undergo hip arthroplasty conventionally or with imageless computer navigation. Postoperatively, a CT scan was performed of the pelvis and lower limb. Using a dynamic CT planning software package, the cup and stem position was measured and compared to the position expected by the three operating surgeons in control cases and the position given by the navigation unit in the study group. Change in leg length was measured clinically and compared with the navigation predicted leg length change. Statistical analysis was performed by a statistician.

Results: Thirty nine navigated hips (29 female, 10 male) and forty one control hips (26 female, 15 male) were recruited. In the navigated group, the mean age was 65.7 and mean BMI was 29.1. In the control group, the mean age was 64.7 and the mean BMI was 29.4 in the control group. Uncemented, securfit/trident hips were used in 18 navigated cases and 20 control cases, with all other cases being cemented Exeter stems and contemporary cups. None of these differences were significant using the Mann-Whitney test. The mean operating time was 128 minutes for navigated hips and 84 minutes for controls, the difference significant at p< 0.005 using t-test.

There was no significant correlation between clinical leg length change, measured in the operating theatre and the leg length change predicted by navigation. Accuracy of cup and stem placement was assessed by comparison of the homogeneity of variances, the Levene statistic, in the navigated and control groups. The range of cup inclination, cup version and stem version was significantly narrowed in the navigation group (p< 0.05).

Conclusion: Computer navigation improves the accuracy of component placement in hip arthroplasty with respect to cup version, cup inclination and stem version with either cemented or uncemented hips.

Study Design: A consecutive retrospective cohort including all patients treated by a single consultant spinal surgeon (BJCF) with targeted foraminal epidural steroid injection (FESI) for radicular pain.

Objective: To assess the efficacy of targeted foraminal epidural steroid injection (FESI) for radicular pain in preventing surgical intervention.

Summary of Background Data: 90% of sciatica resolves within 90 days. Beyond this period, decompresssive surgery for pain relief maybe considered. Open surgery however carries attendant risk including nerve root injury, dural laceration, cauda equina syndrome, deep infection, recurrent disc prolapse, epidural fibrosis and post-discectomy lumbar instability. Peri-radicular infiltration of local anaesthetic and steroid has been shown to reduce pain, at least in the short term. We were interested in whether FESI could obviate the need for surgery in refractory cases of nerve root pain.

Methods: 83 consecutive patients (45 female, 38 male) with a mean age of 51 years (range 24 to 87) presenting between November 2000 and February 2003 with radicular pain were treated with targeted FESI. 55 patients had a principal diagnosis of disc prolapse, 20 had lateral canal stenosis and 8 had degenerative spondylolisthesis. Fourteen had previous surgery and 38 had previous caudal or lumbar epidural injections.

Outcome Measures: Pain was assessed using the Visual Analogue Score and disability by the Oswestry Disability Index. The product-limit method of Kaplan Meier was used to assess the time to further procedure or the date of last review.

Results: 21 of 83 patients (25.3%) underwent an open procedure (discectomy/decompression) within the designated time period (median 20 months). Median time to open procedure was 6.5 months (mean 8.2 months). Repeat FESI was required in 16 patients (19.2%). The remaining 46 (55.4%) patients avoided any further procedure at a median of 20 months (range 13 to 36). No complications resulted from these procedures.

Conclusions: Targeted foraminal epidural steroid injection can resolve radicular pain caused by varying pathologies. Surgical procedures (decompression/discectomy) can be avoided in 74.7% of cases up to a median of 20 months thereby avoiding unnecessary surgical risk.