Abstract

Abstract

Total knee arthroplasty (TKA) aims to alleviate pain and restore joint biomechanics to an equivalent degree to age-matched peers.

Zimmer Biomet's Nexgen TKA was the most common implant in the UK between 2003 and 2016. This study compared the biomechanical outcomes of the Nexgen implant against a cohort of healthy older adults to determine whether knee biomechanics is restored post-TKA.

Patients with a primary Nexgen TKA and healthy adults >55 years old with no musculoskeletal deficits or diagnosis of arthritis were recruited locally.

Eligible participants attended one research appointment. Bilateral knee range of motion (RoM) was assessed with a goniometer. A motorised arthrometer (GENOUROB) was then used to quantify the anterior-posterior laxity of each knee. Finally, gait patterns were analysed on a treadmill. An 8-camera Vicon motion capture system generated the biomechanical model.

Preliminary statistical analyses were performed in SPSS (α = 0.05; required sample size for ongoing study: n=21 per group).

The patient cohort (n=21) was older and had a greater BMI than the comparative group (n=13). Patients also had significantly poorer RoM than healthy older adults. However, there were no inter-group differences in knee laxity, walking speed or cadence. Gait kinematics were comparable in the sagittal plane during stance phase. Peak knee flexion during swing phase was lower in the patient group, however (49.0° vs 41.1°).

Preliminary results suggest that knee laxity and some spatiotemporal and kinematic parameters of gait are restored in Nexgen TKA patients.

While knee RoM remains significantly poorer in the patient cohort, an average RoM of >110° was achieved. This suggests the implant provides sufficient RoM for most activities of daily living. Further improvements to knee kinematics may necessitate additional rehabilitation.

Future recruitment drives will concentrate on adults over the age of 70 for improved inter-group comparability.

The patella is a complex sesamoid bone within the quadriceps enhancing mechanical advantage of the extensor mechanism. Depending on activity, the patella magnifies either force or displacement; behaving as a lever, by redirecting quadriceps force it also acts as a pulley.

This prospective case-controlled study evaluates the outcome of chronic combined anterior cruciate ligament (ACL) & posterolateral corner (PLC) knee reconstruction.

Twenty-six patients (23 male) underwent combined ACL & PLC reconstruction between October 2001 and October 2006 (Group ACL/PLC). Mean age 30.2 years (range 17–44). Mean follow-up 51 months (range 27–109). The commonest mode of injury was football. Seven patients had concomitant lateral, and 9 medial meniscal procedures, 1 osteochondral defect was micro-fractured. All procedures were performed at the same operation. Prospective scoring was done pre-operatively and 3,6,12, and 24 months post-op using Lysholm, IKDC 2000 and KOOS scoring systems. These scores were compared to an age, sex and injury matched control group of patients who also underwent ACL reconstruction without posterolateral corners injury (Group ACL).

Functional scores showed a significant improvement in all patients in both ACL/PLC and ACL groups postop (p< 0.05). Pre-op scores for Lysholm (p=0.005), IKDC (p=0.03), KOOS sports (p=0.03) and quality of life (QOL) (p=0.03) were significantly lower in Group ACL/PLC compared to Group ACL. Other significantly reduced KOOS scores were - sports 12 (p=0.04) & 24 months (p=0.004); and QOL 12 (p=0.01) & 24 months (p=0.006).

Conclusions: Injury to the posterolateral stabilizing structures of the knee usually occurs in association with other ligamentous injuries. The recognition and adequate management of this injury is crucial. Knees with combined ACL & PLC injuries have reduced function compared to ACL injuries alone. Patients undergoing combined ACL & PLC reconstruction should be made aware that the nature of their injury is such that postoperatively they may have ongoing functional limitations with respect to return to sport and quality of life.

The purpose of this study was to evaluate the outcome of posterior cruciate ligament (PCL) reconstruction with a double tunnel technique, using prospective pre & post-operative functional scoring and clinical evaluation.

We reviewed those patients who underwent PCL reconstruction between October 2001 and October 2006. 24 patients were identified, 23 male and 1 female. Mean age 30.1 years (range 17–43). Mean follow up 56 months (range 29–86). The commonest mode of injury was football. 3 patients had isolated PCL injuries, 21 had concomitant knee ligament injuries which were treated surgically at the same operation. Patients were prospectively scored pre-operatively and at 3, 6, 12 & 24 months post-op using the Lysholm, IKDC 2000 & KOOS scoring systems. These scores were compared to an injury matched control group who underwent comparable knee ligament reconstructions, but who had intact PCL’s.

The knee scores showed a significant improvement in all PCL reconstructed patients post-op (p< 0.05). However, significant differences were found between the PCL reconstructed and PCL intact groups. Both groups had high return to employment and return to sports rates. We describe our method of double tunnel reconstruction.

Conclusions: PCL injury is usually associated with concomitant soft tissue knee injuries. PCL deficiency contributes significantly to the morbidity of the multiple ligament injured knee. Reconstruction with the double tunnel technique described gives excellent functional improvement and high rates of return to employment and sports.

Background: Osteoarthritic patients needing a TKA give pain as the major reason for being unable to exercise to lose weight. Weight gain in turn worsens the process of osteoarthritis, this feeds into the vicious cycle. Following a TKA, patients should ideally be able to exercise more and hence lose weight. We assessed this hypothesis in our prospective study by calculating BMI. BMI has been proven in previous studies to be a good reflection of body fat.

Materials and Methods: We prospectively followed up 94 patients in the knee arthroplasty clinic. Height, pre operative weight and post operative weight at 12 months were measured. All the peri-operative factors in all the patients were constant. We then calculated the pre and post operative BMI.

Results: Most of our patients at the 12 month follow up showed to have an increase in BMI. This difference was however not found to be statistically significant.

Conclusion: The result obtained in our study was contrary to previous studies which have shown significant change. We conclude that pre-operative pain alone is not a limiting factor in patient BMI changes peri-operatively.

Aims: To assess the results of Anterior Cruciate Ligament (ACL) reconstruction at a minimum of two years follow-up, using the Rolimeter [AIRCAST, Europe] as an adjunct to routine knee examination and subjective scoring systems.

Methods: The Warrington Knee Injury database was initiated in June 2001 and data from all knee ligament injuries has been collected prospectively, from preoperative status through to all follow up assessments. Inclusion criteria for our study were, all ACL reconstructions performed by the senior author with minimum 24 months follow up; other ligaments being intact and presence of a normal contralateral knee.

50 patients satisfied the inclusion criteria. There were 41 males and 9 females in ages ranging from 17 to 51 (mean 30.6 years), with no significant difference in age between sexes. Hamstring grafts were used in 29 knees and Bone-Patellar tendon – Bone (BPTB) grafts in 21. Knee laxity was measured using the Rolimeter with IKDC knee examination and functional assessments using the Lysholm, IKDC and KOOS scoring systems.

Results: 20/21 of patients with BPTB grafts (95.2%) and 26/29 of patients with Hamstring grafts (89.7%) achieved normal or near normal knee laxity compared to their opposite knee. The Range of movement in 48 of 50 knees (96%) fell within normal or near normal limits according to IKDC description (Lack of extension < 3 degrees and lack of flexion < 10 degrees). Two patients with abnormal range of movement had a similar lack of movement preoperatively. Though none of the knees were abnormally tight (AP laxity difference < -3), there was a relationship between knee tightness and lack of extension, but this was not statistically significant. There was no association between age or sex of patient and lack of movement. The mean IKDC, Lysholm and KOOS symptom scores were 80.45, 87.3 and 81.3 respectively.

Conclusions: We have achieved a normal or near normal AP laxity in 92% of our ACL reconstructions on assessment at 2 years postoperatively. We report no signifi-cant difference in outcome between use of Hamstring or BPTB grafts. The functional outcome has been optimal as revealed by subjective evaluation.

Purpose: To subjectively assess and present the outcome after ACL reconstruction with minimum follow-up of 24 months.

Methods: Our knee injury database was established in June 2001. Data were collected prospectively for all knee ligament reconstructions carried out by a single surgeon. The database has a prospectively studied consecutive series where all the patients surveyed completed the Lysholm, KOOS and IKDC 2000 questionnaires preoperatively and at 3, 6, 12 and 24 months postoperatively. Our knee injury database comprises of 163 patients who had ACL reconstruction in which Hamstrings were used in 120 cases and Bone Patella-Tendon Bone (BPTB) grafts in 43. This includes 27 complex reconstructions and 12 revisions (11 from other centres).

Results: Fifty-six of the 79 patients (70.8%) who were at least 2 years post ACL reconstruction attended for their 2 year review. Majority were male patients(90%) and both attendees and non- attendees were of a similar age (30.5 /30 respectively) and did not exhibit a statistically significant difference in their pre op or early post op scores. In the non-attendee group 2 were students, 1 emigrated, 1 registered as unemployed, 7 no employment status and 3 did not consent to such follow-up. The mechanism of injury was, 62 as sporting injury (24 contact/38 non-contact sport), 3 road traffic accidents and 8 activities of daily living and 2 not recorded. The mean scores were, IKDC – 77.14, Lysholm – 83.96 and KOOS symptom – 81.6.

Conclusions: All subjective evaluation questionnaires (KOOS, Lysholm and IKDC) revealed a progressive trend in our patients. We found that in the KOOS, a multidimensional patient completed aggregated score, the Quality of Life (QoL) dimension exhibited results which were interestingly not correlating with the other dimensions of the questionnaire, with patients who scored < 50% occupying manual or non-administrative positions at work

Purpose: To assess the results of ACL reconstructions carried out at our institution in a non-elite cohort of patients with regards to return to active sports post reconstruction.

Materials & Methods: Seventy-five (71%) of 106 patients who underwent reconstruction of isolated ACL tears between June 2001 and August 2004 performed by the senior author completed a newly designed questionnaire (incorporating Cincinnati Sports Activity Scale [CSAS]) to help us fully assess their return to sports and to elucidate reasons if not returning to pre-injury level. 55 were completed at follow up, with objective clinical assessment and other subjective questionnaires [KOOS, IKDC and Lysholm] and 20 were done through telephone interview.

Results: All 75 patients were involved in sports at CSAS Levels 1 & 2 prior to their injury and 39 (52%) had to drop to level 4 after injury. Following reconstruction 61 patients (81.3%) returned to CSAS 1 & 2 levels. 28 of 30 patients (93.3%) operated within 2 years from injury achieved pre-injury CSAS levels compared to 33 of 45 (73.3%) with a longer interval. The mean Lysholm, IKDC and KOOS Sports scores at 12 to 24 months follow up revealed a progressive trend and were 84.9, 76.3 and 73.6 respectively.

One reason for not returning to pre–injury intensity of sports was that many (71.7%) expressed fears of instability though most (70%) had no instability on playing. 77.8% of non-returners who were more than 30 years age reasoned not wanting to risk re-injury compared to 36.8% in the under 30 group. More significantly, 44.4% of over 30s said they were planning to drop their sporting level anyway compared to 5.5% in the younger group.

Conclusion: ACL reconstruction is best done as early as possible after injury for persons intending to return to competitive sports. The results are even better after early intervention in younger patients. Psychosocial issues play a significant role in return to active sports.

Introduction: This prospective study is designed to evaluate PCL reconstruction using the arthroscopic ‘double bundle technique’ in a consecutive series of patients with multiple ligament instability.

Methods: 12 consecutive patients who underwent arthroscopic posterior cruciate ligament reconstruction at Warrington Hospital for a combined ligament injury with PCL tear between 2001 and 2004 were included in the study. The indication for surgery was functional disability of the knee due to pain and instability. All were male patients with an average age 33 years (range 18 to 44). Average time from injury to surgery was 31.5 months (range 1 day to 96 months). The evaluation parameters included functional assessment, clinical examination, and functional score. All data was collected prospectively. The average period of follow up was 23months (range 9 to 50 months)

Results: Using the IKDC subjective assessment 63% of the patients had normal/near normal knee function (range 16 to 94). On Lysholm scoring 71% reported good or excellent results. On objective examination 83% had abolition of reverse pivot with 91% showing no evidence of PLC instability.

Conclusions: Arthroscopic double bundle PCL reconstruction in this study produced a satisfactory clinical outcome in terms of return to function objective assessment and symptom improvement. The technique has improved results in terms of outcome than previous reports in the literature would suggest.

Introduction: Instrumented arthrometry is a widely used technique for the quantification of cruciate ligament laxity. It is used both before and after surgery. The Rolimeter(Aircast, Europe) is used in such scenarios. It has several advantages over its cousins; it is more compact, lighter, less expensive and amenable to sterilization techniques. The other leading arthrometers have however had over 15 years of clinical use and their reliability has been thoroughly assessed. Muellner et al found no significant difference in the intra-tester and inter-tester results obtained on Rolimeter assessment of the knees of un-injured healthy subjects. Our study assessed the inter-tester and intra-tester variability when the Rolimeter is applied to patients with unilateral ACL-deficient knees. It also examines whether the level of experience of the examiner influences the results in this group of patients.

Materials and Methods: Six examiners each examined thirty-three subjects on two occasions. One examiner was medically qualified but had never performed a Lachman or anterior drawer test. Two examiners were qualified physiotherapists who routinely examined knees, but had never used a Rolimeter. One medically qualified examiner was considered to be of intermediate experience.Two examiners were regarded as expert Rolimeter users.For each examination a Rolimeter reading was taken three times with the knee at 30 degrees of flexion and three times at 90 degrees of flexion for both knees.The interval between examinations was at least thirty minutes. All the readings were acquired on the same day. The examiners were blinded to whether the subject was known to be ACL deficient or not. The results of the examinations were entered onto a data-base.Repeated measures analysis of variance was used to test for the effects of the following factors, difference between examiners, reproduction of results between examinations.

Results: There was no significant difference between each set of measures for each subject between examinations (p=0.767), indicating that the measurement procedure was reliable. Measurements were significantly higher in patients with ACL-deficient knees compared to the control group (p< 0.001) confirming the sensitivity of the Rolimeter to help diagnose ACL-deficient knees. The in-experienced examiner’s measurements were lowest and were more reliable. The examiner with the intermediate experience was the most un-reliable. Both experienced examiners were in close agreement.

Conclusion: We have demonstrated that the rolimeter is reliable in the assesment of ACL deficient patients regardless of the experience of the examiner.

Introduction: Traumatic knee dislocations are rare but devastating injuries. We have evaluated the clinical results of ligament repair and reconstruction. Knee dislocation was defined as an acute event that produced multidirectional instability with at least 2 of the 4 major ligaments disrupted.

Materials: Twenty-one patients with 22 knee dislocations presented between 1994 and 2001. There was one vascular and one common peroneal nerve injury. Eight (38%) patients were treated in the acute period (< 14 days), 5 (24%) had reconstructions within 1 year of injury. The remainder were late reconstructions. The patients were evaluated at mean follow-up of 32 months (11 to 77). This included ROM measurement, clinical and instrumented ligament laxity testing. Posterior stress view with 10kg weight was used to evaluate the PCL reconstruction. Function was evaluated using the IKDC chart, the Lysholm Score, the Tegner Activity Level, the Knee Outcome Survey and WOMAC.

Results: The mean extension deficit was 6.8 degrees (0–25) and mean flexion deficit was 8.6 degrees (0–20). Of the ACL reconstructions, 4 knees had 0–3mm side-to-side difference, 15 knees had 3–5mm and 1 knee had 6–10mm. Of the PCL reconstructions, 2 were within 3–5mm of side-to-side difference, 9 knees were 6–10mm and 4 were more than 10mm. Posterolateral corner repair/reconstructions appeared durable. None of the knees were IKDC Grade A, 8 knees were Grade B, 9 were as Grade C and 5 were Grade D. The mean Lysholm Score was 81 (66–100) and the mean Tegner Activity Level was 4.9 (1–7). The mean Knee Outcome Survey score was 75 (41–99). Acutely treated knees had better scores than late reconstructions.

Conclusion: Our study has demonstrated good function in the operatively treated knee dislocations at 1–7 years. Nearly all had few problems with daily activities. The ability to return to high-demand sports and heavy manual labour was less predictable.

Aims: The results of surgical repair and reconstruction of knee dislocations were reviewed at average follow-up of 32 months. Methods: Twenty-one patients with 22 knee dislocations presented between 1994 and 2001. There was one vascular and one common peroneal nerve injury. Eight (38%) patients were treated in the acute period (< 14 days), the remainder were late reconstructions. The patients were evaluated at mean follow-up of 32 months (11 to 77). This included ROM measurement, clinical and instrumented ligament laxity testing. Posterior stress view with 10kg weight was used to evaluate the PCL reconstruction. Function was evaluated using the IKDC chart, the Lysholm Score and the Tegner Activity Level. Results: The mean Lysholm score in the acute group was 87 (range 81 to 93) and in the delayed group 75 (range 53 to 100), the mean Tegner activity rating was 5 in the acute group and 4.4 in the delayed group. IKDC assessment revealed no differences between the two patient groups. Instrumented testing of knee stability indicated better results for ACL reconstructions performed in the acute phase but no difference in the outcome of PCL reconstruction. There was no difference in loss of knee movement between the two groups. Conclusions: Good function can be obtained in the operatively treated knee dislocations at 1–7 years. Although the differences were small, the outcome in terms of overall knee function, activity levels and anterior tibial translation were better in those knees reconstructed within two weeks of injury.

Traumatic knee dislocations are rare but devastating injuries. We have evaluated the clinical results of ligament repair and reconstruction. Knee dislocation was defined as an acute event that produced multidirectional instability with at least 2 of the 4 major ligaments disrupted.

Twenty-one patients with 22 knee dislocations presented between 1994 and 2001. There was one vascular and one common peroneal nerve injury. Eight (38%) patients were treated in the acute period (< 14 days), 5 (24%) had reconstructions within 1 year of injury. The remainder were late reconstructions. The patients were evaluated at mean follow-up of 32 months (11 to 77). This included ROM measurement, clinical and instrumented ligament laxity testing. Posterior stress view with 10kg weight was used to evaluate the PCL reconstruction. Function was evaluated using the IKDC chart, the Lysholm Score, the Tegner Activity Level, the Knee Outcome Survey and WOMAC.

The mean extension deficit was 6.8 degrees (0–25) and mean flexion deficit was 8.6 degrees (0–20). Of the ACL reconstructions, 4 knees had 0–3mm side-to-side difference, 15 knees had 3–5mm and 1 knee had 6–10mm. Of the PCL reconstructions, 2 were within 3–5mm of side-to-side difference, 9 knees were 6-10mm and 4 were more than 10mm. Posterolateral corner repair/reconstructions appeared durable. None of the knees were IKDC Grade A, 8 knees were Grade B, 9 were as Grade C and 5 were Grade D. The mean Lysholm Score was 81 (66–100) and the mean Tegner Activity Level was 4.9 (1–7). The mean Knee Outcome Survey score was 75 (41–99). Acutely treated knees had better scores than late reconstructions.

Our study has demonstrated good function in the operatively treated knee dislocations at 1–7 years. Nearly all had few problems with daily activities. The ability to return to high-demand sports and heavy manual labour was less predictable.