Statement of purpose: To study the biology of tendon – bone integration in human hamstring tendon autograft at the femoral tunnel interface

Methods: A total of 70 patients undergoing revision anterior cruciate surgery for both traumatic and atraumatic injury were studied. All surgery was performed under the supervision of the senior author. At time of surgery tissue was taken from the residual graft and femoral tunnel. The demographics of the original surgery, mechanism of failure, patient characteristics were recorded. We have also recorded variables such as tunnel positioning, early rehabilitation, associated ligamentous laxity. Local ethical committee approval has been granted. The specimens were analysed for gross evidence of cell necrosis, macrophage and fibroblast ingrowth (H& E). Vascularity was quantified by multiple high powered field counting. The influence of makers of cell turnover and matrix degradation have been determined by cell staining for TIMP-1, -2 and –3 (Immunohistochemistry) and early correlations drawn between the histological findings and patient factors such as mechanism of reinjury. We have also examined the graft expression of receptors of IGF1, FGF, MMP-1, 7, 8, 11, and 13 as key markers of collagen remodelling.

Results: We have found novel expression of MMP-13 in collagen graft tissue. There is clear evidence in a subgroup of certain patients exhibiting aggressive vascular ingrowth in association with IGF and MMP-11 and −13 expression suggesting a possible regulatory process. Areas of poor cellularity appear to exhibit low levels of MMP-13 but moderate levels IGF-II suggesting an alternative cellular response to graft fixation at the femoral tunnel. There appear to be distinct subgroups of cellular response in patients with atraumatic failure.

Conclusion: This is the first study to the biology of ACL graft failure at the bone tendon interface in a human model. Previous work has been case reports or using a canine model. These have limited application to the clinical work. We have found clear evidence of a processs of graft – host bone integration through neovascularisation. There is evidence of the graft remodelling through local expression of collagen resorptive agents. This work is being extended to look at the role of exogenous factors in augmenting graft integration at the host site.

J Bone Joint Surg Am. 1993 Dec;75(12):1795–803.

Am J Sports Med. 2001 Nov–Dec;29(6):689–98.

Methods Mol Biol. 2001;151:389–97.

Statement of purpose: We studied anterior knee function in a cohort of patients with either osteoarthritis or rheumatoid disease who had undergone knee replacement in a single unit using a standard implant.

We identified a consecutive series of patients who had undergone knee replacement surgery for either osteoarthritis or rheumatoid disease between 1990 and 1995 under the care of a single surgeon using the same implant and surgical technique. There were ninety patients in each group. All were examined and underwent radiography of the anterior compartment. Data was collated for Hospital for Special Surgery (HSS) score, Western Ontario and McMasters Universities Osteoarthritis Index (WOMAC) score, a specific patellar score and a Visual Analog score (VAS).

Results: There were no discernible differences between the rheumatoid and osteoarthritis groups in all the measured scores, with good anterior knee function noted in both.

Conclusion: Based on our outcome studies in a matched group of patients no differences were found for anterior knee function between osteoarthritis or rheumatoid disease. We do not routinely resurface the patella and do not consider there to be any particular indication for such in the rheumatoid disease patient.

We carried out 60 revision procedures for failed porous coated anatomic total knee replacements in 54 patients, which were divided into two groups. The 14 knees in group I had a well-fixed femoral component at surgery which was retained, and in the 46 knees in group II both tibial and femoral components were loose and were revised using a variety of implants. Our review comprised clinical and radiological assessment.

A total of 13 knees required a second revision. Six (42%) in group I failed very early (mean 2.1 years) when compared with seven (15%) in group II (mean 6.8 years). Failure was due to wear of the polyethylene insert by the abraded, retained femoral component (crude odds ratio 4.07; 95% CI 1.07 to 15.5). We recommend a complete change of primary bearing surfaces at the time of revision of an uncemented total knee replacement in order to prevent early wear of polyethylene.

There is little data on the long-term outcome of rotating hinge total knee arthroplasty. We provide a clinical and radiographic assessment of survivorship of the Kinematic rotating hinge total knee arthroplasty (How-medica, Rutherford, NJ), in a series of 72 implants, performed by a single surgeon in one unit, between 1983 and 1997. Survival analysis using known all cause revision revealed a 92% five-year implant survival, but worst-case scenario was 31% at five years.

In a subset of 27 patients we used the Nottingham Health Profile (NHP) to assess prospectively the changes in health-related quality of life following rotating hinge arthroplasty. In this salvage arthroplasty setting we demonstrate a significant improvement in two modalities of the NHP (pain and physical mobility).

Introduction: Arthroscopic A.C.L. reconstruction using Semitendinosus (S.T.) and Gracilis (Gr.) tendons is a popular technique for the treatment of ACL deficient knees. It is common to find accessory tendinous bands (vinculae) arising from these two tendons when harvesting them. The implications are that extra care must be taken with the use of the tendon stripper if one is to avoid cutting the main tendon. Our clinical experience reveals that these connections are highly variable and, contrary to popular thinking, may be present beyond 10cm. proximally.

Aim: Our aim was to map these intertendinous connections and assess their variability using a cadaveric model. In particular we were interested to identify the presence of vinculae arising proximally beyond 10cm.

Procedure: We dissected the tendons of Gr. and S.T. of ten embalmed adult human cadaveric legs. Various vinculae from both tendons were identified and their origin and insertion mapped. All measurements were done using the tibial crest as a reference.

Results: We found that vinculae have a high variability. Bands were seen between tendons, connecting them to the popliteal fascia, sartorius, gastrognemis, pretibial and superficial fascia. Vinculae originated more than 10cm proximally from Semitendinosus and Gracilis in eight and two occasions respectively. There was a constant connection band between S.T. and the grastrocriernius fascia.

Conclusion: Our results confirm that vincular anatomy is more variable than previously reported. Surgeons should be aware of our new finding of vinculae commonly originating beyond 10cm. proximally. This work has prompted us to investigate the role of MRI for pre-operatively templating vinculae.

Purpose: To study the effect of retaining an abraded femoral component on the outcome of primary revision of uncemented total knee prosthesis.

Method: 66 revision procedures for failed uncemented porous coated anatomic (PCA) total knee replacement were performed in 60 patients. At review, four patients had died while two were lost to follow up, therefore 60 knees in 54 patients were included in this prospective study. The principal indications for primary revision were polyethylene wear and loosening of the tibial base plate. 14 patients had a well fixed femoral component and hence were retained while 46 patients had both the components revised. All patients were prospectively assessed prior to surgery, at three months, six months and yearly thereafter. Review comprised clinical and radiological assessment. The mean follow up was 8.4 yrs (7–12 yrs)

Summary of results: The mean pre-operative Hospital for Special Surgery knee score after the first revision improved at a follow up of 8.4yr (7–12yr) giving 39 (65%) excellent, 17 (28.4%) good and four (6.6%) poor results. 13 out of 60 knees needed a further revision. Six of these second revisions which had only the tibial component changed failed very early (mean of 2.1 yr) when compared to the rest (6.8yr), probably due to wear between the abraded retained femoral component and polyethylene insert. The estimated odds ratio (relative risk) of second revision in patients with retained femoral component compared to those with revision of both the components was 4.17 (95% C.I. 1.07 – 15.4).

Conclusion: We recommend exchange of all the components at the time of revision of PCA knee prostheses. Significance: To our knowledge, this is the only study involving such a large number of PCA revisions and looking into the effect of retaining the femoral component compared to changing both the components on the outcome of revision.

Aim: To prospectively determine the functional outcome of revision total knee replacement (TKR).

Method: We carried out a prospective outcome study recruiting 65 consecutive revision total knee replacements carried out by the senior author between 1992 and 1995. The indications for revision were aseptic loosening in 40 cases, instability in 7, infection in 4, and 16 cases for other causes. All patient was assessed preoperatively and at 3 and 12 months postop using the Nottingham Health Profile (NHP) to measure general health status. As part of this ongoing study, followup data is available for 24 patient at 5 years.

Results: There were 65 revisions in 60 patients, 5 being bilateral. There were 37 females and 23 males, with a mean age of 63 years (range 29 to 86 years). The preoperative scores showed that the patient had significant disability related to their failed TKR. Three months postop, there was a significant improvement in the NHP scores for pain and social isolation. At 12 months, the level of pain was again significantly improved over the 3 month score.

At 5 years, the pain score for the revision group deteriorated but remained better than the baseline level. This is in contrast to post primary TKR, where the improvement in pain score was maintained from 3 months onwards.

Conclusion: This study shows a significant improvement in the level of pain following revision knee arthroplasty. However, patients remain significantly disabled afterwards and do not show the very marked improvement in general health seen after primary TKR.

Introduction: The management of the acutely locked knee remains controversial. The incidence of ‘benign’ causes for an acutely locked knee that do not require surgical intervention is perhaps greater than is generally appreciated.

Aim: To study the features of the acutely locked knee, identifying which features are predictive of the cause of the locking.

Patients: Consecutive patients presenting with an acutely locked knee for Orthopaedic consultation were included in the study.

Methods: A prospective cross-sectional study was undertaken to observe the management of acutely locked knees.

Results: To date, forty patients presenting with acutely locked knees have been studied. Thirty-eight underwent examination and arthroscopy under general anaesthesia. 85% of patients were found to have distinct pathology causing a mechanical block to full extension. Eight percent were found to have only degenerative change and two patients unlocked without any surgical intervention. In those patients found to have a mechanical block to extension, consistent features of a definitive injury, joint line tenderness and the presence of an effusion were strongly predictive. We are currently evaluating an algorithm for the pre-operative prediction of remediable mechanical causes of locking.

Discussion: We suggest that patients presenting with acutely locked knees due to a non-mechanical cause can be identified consistently based upon the history and examination alone.

Aim: To determine the quality of life and radiological outcome of the rotating hinge total knee prosthesis as a salvage procedure for failed knee arthroplasty.

Methods: Forty-seven consecutive revision total knee arthroplasties, using the rotating hinge component, implanted between November 1983 and June 1997, were studied. The principal indications for surgery were pain with ligamentous laxity and gross bone loss. There were 43 patients, 11 males, 32 females, 19 left and 28 right, 21 with rheumatoid disease and 22 with osteoarthritis. The mean age at revision was 68 years, mean time from primary procedure to revision of 8 years and a mean number of previous knee procedures of 1.6 (range 1–5). The average time to final follow-up was 5 years. Quality of life was determined using the Nottingham Health Profile (NHP) combined with standard clinical and radiological assessment.

Results: Of the 47 revision procedures, full clinical follow-up information was available on 43 (91.5%), radiographic follow-up on 38 (80.9%). Complications occurred in 10 out of the 47 arthroplasties (21.3%) including 4 deep infections, 2 femoral fractures, 2 patients with clinically apparent aseptic loosening and 2 significant extensor mechanism problems. Survivorship analysis revealed a 5year cumulative implant survival of 89%. Significant improvements in quality of life (pain and physical mobility) were shown at 12 months post-operatively.

Discussion: This is a prospectively-studied series of salvage arthroplasty procedures. We regard quality of life as a key indicator of surgical success after knee arthroplasty. Rotating hinge arthroplasty offers objective and reproducible improvement in quality of life for failed knee arthroplasty with ligamentous instability.

Aim: To prospectively determine whether social deprivation has an effect on the level of disability at presentation and the outcome from total knee replacement (TKR).

Method: A prospective outcome study was carried out between 1992 and 1996, recruiting over 2500 total knee replacements. All patients were assessed preoperatively and at 3 and 12 months postop using the Knee Society (KS) scores for clinical evaluation and the Nottingham Health Profile (NHP) to measure general health status. The Townsend Score was used as the index of social deprivation and was calculated for each patient on the basis of their address.

Results: There was no significant difference between either the Knee Society or NHP scores at baseline and the Townsend Score. This indicated that social deprivation has no effect on the level of the knee arthritis immediately prior to joint replacement, both in terms of patient disability and health status.

There was also no significant difference between either the Knee Society or NHP scores postoperatively and the Townsend Score. This indicated that social deprivation has no effect on the outcome from knee replacement.

Conclusion: This study shows that social deprivation has no significant effect on the level of disability at presentation and the outcome from total knee replacement. This is contrary to previously published reports which have shown worse outcomes in more deprived patients.

A total of 90 patients with an isolated rupture of the anterior cruciate ligament (ACL) had a reconstruction using the ipsilateral patellar tendon secured with round-headed cannulated interference screws. Annual review for five years showed three failures of the graft (two traumatic and one atraumatic); none occurred after two years. Ten patients sustained a rupture of the contralateral ACL. At five years, 69% of those with surviving grafts continued to participate in moderate to strenuous activity. Using the International Knee Documentation Committee assessment, 90% reported their knee as being normal or nearly normal and had a median Lysholm knee score of 96 (64 to 100). Most patients (98%) had a pivot shift of grade 0 with the remaining 2% being grade 1; 90% of the group had a Lachman test of grade 0. The incidence of subsequent meniscectomy was similar in the reconstructed joint to that in the contralateral knee. Radiological examination was normal in 63 of 65 patients. Our study supports the view that reconstruction of the ACL is a reliable technique allowing full rehabilitation of the previously injured knee. In the presence of normal menisci there is a low incidence of osteoarthritic change despite continued participation in sporting activity.

Early implants for total knee replacement were fixed to bone with cement. No firm scientific reason has been given for the introduction of cementless knee replacement and the long-term survivorship of such implants has not shown any advantage over cemented forms. In a randomised, prospective study we have compared cemented and uncemented total knee replacement and report the results of 139 prostheses at five years. Outcome was assessed both clinically by independent examination using the Nottingham knee score and radiologically using the Knee Society scoring system.

Independent statistical analysis of the data showed no significant difference between cemented and cementless fixation for pain, mobility or movement. There was no difference in the radiological alignment at five years, but there was a notable disparity in the radiolucent line score. With cemented fixation there was a significantly greater number of radiolucent lines on anteroposterior radiographs of the tibia and lateral radiographs of the femur.

At five years, our clinical results would not support the use of the more expensive cementless fixation whereas the radiological results are of unknown significance. Longer follow-up will determine any changes in the results and conclusions.