Purpose

Investigate the functional outcome of medial patellofemoral ligament (MPFL) surgery for patella instability.

Compare functional outcome of direct MPFL repair and reconstruction using hamstring graft.

Aim: The purpose of this study was to evaluate the results of transphyseal ACL reconstruction technique in skeletally immature patients.

Material & Methods: Between 2002 and 2008, twenty knees in twenty skeletally immature patients with a mean chronological age of 13.2 years (range, 7 to 16.2 years) underwent transphyseal reconstruction of the anterior cruciate ligament with use of an autogenous quadrupled hamstrings-tendon graft with metaphyseal fixation. Ten knees had additional meniscal surgery. The functional outcome, graft survival, radiographic outcome, and any growth disturbance were evaluated at a mean of 2.2 years (range, 1.0 to 5.9 years) after the surgery.

Results: No patient underwent revision anterior cruciate ligament reconstruction. The mean International Knee Documentation Committee subjective knee score (SD) was 90.5 (10.0) points and the mean Lysholm knee score was 92.2 (10.0) points. The result of the Lachman examination was normal in 18 knees and nearly normal in two; it was not abnormal or severely abnormal in any knee. The mean increase in total height was 7.2 cm (range, 1.2 to 20.4 cm) from the time of surgery to the time of final follow-up. No angular deformities of the lower extremity were measured radiographically, and no lower-extremity length discrepancies were measured clinically. Complications included one case of knee stiffness requiring physiotherapy, one case of persistent pain leading to medial menisectomy for tear and one case of re-injury five months post ACL reconstruction requiring medial meniscus repair.

Conclusion: Excellent functional outcome was noted in skeletally immature patients after transphyseal reconstruction of the anterior cruciate ligament with use of an autogenous quadrupled hamstrings-tendon graft with metaphyseal fixation. There were very few complications and no growth disturbance.

Introduction: The anterior drawer test for anterior cruciate ligament (ACL) deficiency, requires a subjective assessment of joint movement, as the tibia is pulled forward. The aim of this study was to objectively quantify this movement using a magnetic tracking device.

Materials and Methods: Ten patients aged 24 to 44 years were assessed as having unilateral ACL deficiency with conventional clinical tests. These patients were then re-assessed using a magnetic tracking device (Polhemus Fastrak). Patients had magnetic sensors attached around their femurs and tibias using elasticated Velcro straps. The Anterior Drawer test was then performed with the patient lying within range of the system’s magnetic source. The test was performed three times on the normal and injured knees of each patient, using a spring balance to apply a standard 20 lb (=89 N) force. During the tests, sensor position and orientation data was collected with an accuracy better than 1 mm and 1 degree, respectively. The data was sampled at 10Hz and stored on a computer for post-test analysis. This analysis deduced the tibial displacement resulting from each anterior drawer.

Results: During the anterior drawer test the supine patient’s knee is in 90 degrees flexion, with the foot planted on the examination couch. As the tibia is pulled anteriorly, it rotates upwards from the foot and the femur experiences a corresponding rotation from the hip. These complex coupled movements are best quantified in terms of absolute displacement of the tibia from the femur. In the normal knees, the mean displacement of the tibia from the femur was 4.2 mm (SD=1.6). In comparison the ACL deficient knees had a mean displacement of 6.3 mm (SD=2.9). This is 50 % more. A paired t test of this data showed a highly significant difference, with P = 0.005.

Conclusion: This study has quantified the movement produced during the Anterior Draw test for ACL deficiency. The tracker’s lightweight sensors caused minimal disturbance to the established clinical test. The system therefore provides objective measurement data to augment the clinicians subjective assessment.

Introduction: The Lachman test for anterior cruciate ligament (ACL) deficiency, requires a subjective assessment of joint movement, as the tibia is pulled anteriorly. This study has objectively quantified this movement using a magnetic tracking device.

Materials and Methods: Ten patients aged 21 to 51 years were assessed as having unilateral ACL deficiency with conventional clinical tests. These patients were then reassessed using a magnetic tracking device (Polhemus Fastrak). Patients had magnetic sensors attached around the femoral and tibial mid-shafts using elasticated Velcro straps. The Lachman test was then performed with the patient lying within range of the system’s magnetic source. The test was performed three times on the normal and injured knees of each patient. During the tests, sensor position and orientation data was collected with an accuracy better than 1 mm and 1 degree, respectively. The data was sampled at 10Hz and stored on a computer for post-test analysis. This analysis deduced the tibial displacement resulting from each Lachman pull.

Results: The main Lachman movement is an anterior displacement of the tibia with respect to the femur. The mean anterior movement for the normal knees was 5.6 mm (SD=2.5). By comparison the ACL deficient knees had a mean anterior movement of 10.2 mm (SD=4.2). This is 82 % more. A paired t test of this data showed it to be highly significant with P = 0.005. In addition to the anterior movement, there was also a small proximal tibial movement. In the normal knees the mean movement was 0.7 mm (SD=1.9). In the injured knees the mean movement was 2.1 mm (SD=3.4). However, this difference was not significant (P = 0.12).

Conclusion: This study has quantified the movement produced during the Lachman test for ACL deficiency. The results compare well with reported results from similar arthrometer tests[1]. The main advantage of the magnetic tracker is that its lightweight sensors cause minimal disturbance to the established clinical test. It therefore offers a convenient and non-invasive method of investigation.

There has been speculation as to whether the outcome of revision total knee arthroplasty (TKA) is as successful as primary TKA. The purpose of this study was to assess patient outcomes following revision TKA and compare them to patient outcomes following primary TKA.

This study collected data prospectively from patients operated upon by one surgeon using one prosthesis in each group. Patients completed SF12 and WOMAC questionnaires pre-operatively and at six and twelve months post-operatively. In the primary TKA group there were 84 patients. In the revision TKA group there were 60 patients. Statistical analysis was performed using paired and unpaired t-tests.

Results showed that the improvements in SF12 physical scores and WOMAC pain, stiffness and function scores in both primary TKA and revision TKA patients were statistically significant (p < 0.0001). There was no significant difference in the magnitude of the improvement in SF12 physical (p = 0.7145) and WOMAC pain (p = 0.0902), stiffness (p = 0.1557) and function (p = 0.3152) scores between the primary and revision patients following surgery.

The mental scores of patients in both groups showed no significant difference following surgery (Primary p = 0.823, Revision p = 0.7095).

The findings show that primary and revision TKA lead to a comparable improvement in patient perceived outcomes of physical health parameters.

However, there is no significant improvement in patient perception of mental health.