The aim of this study was to assess the results of combined arthroscopically assisted posterior cruciate ligament reconstruction and open reconstruction of the posterolateral corner in patients with chronic (3 months or more) symptomatic instability and pain. A retrospective analysis of all the patients who had a combined reconstruction of the posterior cruciate ligament and the posterolateral corner between 1996 and 2003 was carried out. Nineteen patients who had the combined reconstruction were identified from the database. All the patients were assessed pre- and post-operatively by physical examination and three different ligament rating scores. All the patients also had weight bearing radiographs, MRI scans and an examination under anaesthesia and arthroscopy pre-operatively. The PCL reconstruction was performed using an arthroscopically assisted single anterolateral bundle technique and the posterolateral corner structures were reconstructed using an open Larson type of tenodesis.Objective
Patients & methods
Early stabilisation after an anterior cruciate ligament (ACL) rupture reduces future meniscal injury. We may therefore expect protection of articular cartilage from ACL reconstruction, but this has yet to be shown. Our aim wasto determine the effect of meniscal injury on the long term risk of osteoarthritis (OA) following ACL reconstruction using Single Photon Emission Computed Tomography (SPECT, a 3 dimensional radionuclide scan). We studied a prospective series of 31 patients (mean age at injury of 29 years) who had bone-patellar tendon-bone ACL reconstruction for unstable, ACL deficient knees. Mean follow-up was 10 years (range 9-13). Patients were separated into two groups according to the status of their menisci at the time of ACL reconstruction, those with intact menisci in group 1 (n=15) and those who required partial meniscectomy in group 2 (n=16). The contra-lateral normal knee was used as a control. All knees were clinically stable with high clinical scores (mean Lysholm score 93 and mean Tegner activity score 6). In group 1 (intact menisci) only one patient (7%) had clinical symptoms of OA and was the only patient with increased uptake on SPECT compatible with early OA. In group 2 (partial meniscectomy), two had clinical symptoms of osteoarthritis, and five patients (32%) had increased uptake on SPECT compatible with early OA. None of the control knees had early OA on SPECT. The prevalence of OA 10 years post ACL reconstruction, using the most sensitive investigation available, is very low in patients who had intact menisci (7%), but increases 5 fold (32%) if a meniscal tear was present. We recommend early ACL reconstruction to preserve the menisci to minimise the long term risk of OA.
Retrieval study:
14 knee replacement components were retrieved after revision procedures. The average surface roughness (Ra) of the articulating regions of each condyle was measured by surface profilometry and compared to Ra of non-articulating regions, which acted as controls on each implant. In vitro testing:
Pin-on-plate testing of 6 paired CoCr pins and vacuum γ-irradiated UHMWPE discs was carried out under a force of 2.3kN at 1Hz to investigate how the articular Ra of CoCr pins varied with increasing number of cycles. Ra was measured at 0, 10, 100 and 1000 cycles using surface profilometry.
Retrieval analysis:
Average medial femoral condyle Ra was significantly greater than control Ra (p=0.040). Average lateral femoral condyle Ra was not significantly greater than control Ra (p=0.158). Significantly higher average Ra was seen on the medial condyles when compared with the lateral condyles (p <
0.05). 8/14 retrieved femoral components had ≥1 significantly roughened condyle (p<
0.05). In vitro testing:
At 100 and 1000 cycles the Ra of the CoCr pins was significantly greater than Ra at 0 cycles (p<
0.05).
Reconstruction was done by a standard 4-strand hamstring technique using an endobutton proximally and a spiked washer and screw distally in the tibia. The IKDC, Lysholm and Tegner scores were used to assess the knees pre and post-operatively. Stability was measured using the KT-1000 arthrometer.
The incidence of osteoarthritis (OA) after an ACL reconstruction is not clear. Reports estimate between 12% and 61% at 8 years post ACL reconstruction. Single Photon emission Computed Tomography (SPECT) scanning (a 3 dimensional radionuclide bone scan) is a sensitive and quantitative method of assessing knee OA, with abnormalities appearing before plain xray and arthroscopic changes.
We reviewed 31 of 33 consecutive patients with intra-articular fractures of the knee at 6 to 22 years (average 14). Of these, 77% had excellent or good results; the others had various degrees of degenerative osteoarthritis. There was no significant difference between the results after surgical or conservative treatment. Secondary degeneration was not related to cause or type of fracture, but its incidence increased with the patient's age at the time of injury, though not with the length of follow-up. Early mobilisation appeared to be beneficial in preventing later degenerative changes.
Minor degrees of malalignment of the patella and anatomical abnormalities including a flattened sulcus angle and an increased ratio between patellar tendon length and patellar length (PT:P) have been suggested as predisposing factors in the causation of chondromalacia patellae, as well as patellar instability. In order to confirm or refute this hypothesis a prospective study has been performed comparing the congruence and sulcus angles and the PT:P ratio in a group of 35 patients with chondromalacia confirmed by arthroscopy and a group of 33 patients with instability, with those of a group of 50 knees in normal volunteers. While there was a statistically significant correlation between an increased sulcus and congruence angle and a high-riding patella in patients with instability, no correlation could be identified in patients with idiopathic chondromalacia.
The transcutaneous oxygen pressure (tcPO2) was measured by a polarographic technique in the legs of 161 volunteers and compared with the levels found in 62 patients with ischaemic skin due to peripheral vascular disease. The results show that the tcPO2 was related to the degree of ischaemia and, in many cases, was a more accurate guide to the viability of the skin than clinical assessment. Measurement of the transcutaneous oxygen pressure in the leg at the site of amputation in 24 patients with peripheral vascular disease showed that a preoperative level greater than 40 millimetres of mercury at an electrode temperature of 44 degrees Celsius was necessary for the skin of the stump to heal. The technique is simple, non-invasive and reliable. The tcPO2 accurately reflects the physiological and pathological changes in the circulation of the skin. It has potential in many fields of surgery where careful assessment of the viability of the skin is necessary.