Timothy Lording

Progression of medial osteoarthritis and long term results of lateral unicompartmental arthroplasty: 10 to 18 year follow-up of 54 consecutive implants

INTRODUCTION The literature results of unicompartmental knee arthroplasty (UKA) for isolated lateral osteoarthritis (OA) are not as good as for isolated medial OA. In 1988 our department started using a UKA with a fixed, all polyethylene tibial component and a resurfacing femoral component. The aim of this retrospective study is to report on the progression of medial OA and the long term results of this prosthesis implanted for isolated lateral OA, at a minimum follow up of ten years. MATERIALS AND METHODS From January 1988 to October 2003, we performed 54 lateral UKAs in 52 patients. All patients had isolated lateral OA, which was post-traumatic in three cases. The mean age at the time of the index procedure was 72.2 ± 15.2 years. Forty-six UKAs in 44 patients were available for follow-up. The mean duration of follow-up was 14.2 years (minimum ten years; range 10.2-18 years). RESULTS At final follow-up, seven had undergone a second operation, three were revised to total knee arthroplasty (TKA), three had medial UKAs implanted for progression of medial disease, and one was converted to TKA for tibial tray malpositioning. No revision surgery was necessary for wear, infection or progression of patellofemoral OA. The mean Knee Society Score (KSS) knee score was 95.1 points and mean KSS function score was 82.2 points. The mean range of motion was 132.6° (range, 115-150°). Implant survival was 94.4% at ten years and 91.4% at 15 years. CONCLUSION The use of a UKA with a fixed, all polyethylene tibial bearing and a femoral resurfacing implant is a reliable option for the management of isolated lateral knee osteoarthritis. We have demonstrated excellent functional results and implant survival in the long term. The most significant factor leading to reoperation is progression of medial disease.

Chondral Injury in Patellofemoral Instability

Objective: Patellofemoral instability is common and affects a predominantly young age group. Chondral injury occurs in up to 95%, and includes osteochondral fractures and loose bodies acutely and secondary degenerative changes in recurrent cases. Biomechanical abnormalities, such as trochlear dysplasia, patella alta, and increased tibial tuberosity-trochlear groove distance, predispose to both recurrent dislocations and patellofemoral arthrosis. Design: In this article, we review the mechanisms of chondral injury in patellofemoral instability, diagnostic modalities, the distribution of lesions seen in acute and episodic dislocation, and treatments for articular cartilage lesions of the patellofemoral joint. Results: Little specific evidence exists for cartilage treatments in patellofemoral instability. In general, the results of reparative and restorative procedures in the patellofemoral joint are inferior to those observed in other compartments of the knee. Conclusion: Given the increased severity of chondral lesions and progression to osteoarthritis seen with recurrent dislocations, careful consideration should be given to early stabilisation in patients with predisposing factors.

A Robotic System for Measuring the Relative Motion Between the Femur and the Tibia

The goal of the robotic system for measuring the relative motion between the femur and the tibia is to provide the clinician with objective parameters (numbers and graphs) which correlate with specific injuries in the knee. In this chapter the sequence of events that shaped the evolution of the robotic system is described. Several key issues that were encountered during the years of development of the robotic system are discussed, as are sources of error during biomechanical knee testing. Detail is given on the problems associated with the management of error using the robotic system. Finally, clinical examples of using the robotic system to examine two patients are presented. On balance, the robotic system allows for the reliable recording of objective parameters of the injured knee while minimizing error. The objective results obtained using the robotic system can provide the clinician with information that will allow for the best treatment plan for the patient with an injured knee.

Proximal tibial bony and meniscal slopes are higher in ACL injured subjects than controls: a comparative MRI study

PurposeIncreased tibial slope is reported as a risk factor of non-contact anterior cruciate ligament (ACL) injury, but the effect of the soft tissues on slope remains unclear. The primary aims of this study were to compare the tibial bony and soft tissue slopes between patients with and without ACL injury, and to investigate the relationship between the meniscal slopes (MS) and the tibial bony slope. Our hypothesis was that the menisci would correct the inclination of the bony tibial slope towards the horizontal.MethodsUsing magnetic resonance imaging (MRI), the lateral and medial tibial slopes (LTS, MTS) and lateral and medial meniscal slopes (LMS, MMS) were compared in 100 patients with isolated ACL injury and a control group of 100 patients with patello-femoral pain and an intact ACL.ResultsRepeated-measures analysis of variance showed good inter- and intra-observer reliability for both bony and soft tissue slopes (ICC (0.88–0.93) and (0.78–0.91) for intra- and inter-observer reliability, respectively). The LTS and MTS were significantly greater in the ACL injury group (10.4 ± 3.1 and 9.4 ± 3.3) than in the control group (7.3 ± 3.4 and 7.0 ± 3.7). Similarly, the LMS and MMS were significantly greater in the ACL injury group (4.7 ± 4.7 and 6.0 ± 3.4) than the control group (0.9 ± 4.8 and 3.7 ± 3.6). In both groups, the lateral bony tibial slope was greater than the medial bony tibial slope, but the medial soft tissue slope was greater than the lateral soft tissue slope.ConclusionIncreased tibial slopes, both bony and meniscal, are risk factors for ACL injury. As the meniscus tends to correct the observed slope towards the horizontal, loss of the posterior meniscus may potentiate this effect by increasing the functional slope.Level of evidenceIII.

Three dimensionalCT analysis of femoral tunnel position after ACL reconstruction. A prospective study of one hundred and thirty five cases

BackgroundOne of the principal causes for failure of anterior cruciate ligament reconstruction (ACL) is femoral tunnel mal-position. Several studies compare the position of femoral tunnels achieved with various techniques, with small series and using a quadrant assessment method.Questions(1) What is the incidence of anatomical positioning of the intra-articular femoral tunnel aperture in primary ACL reconstruction in a university knee surgery? (2) What are the main errors in positioning?Methods3D-CT scans were performed after primary ACL reconstruction in 135 consecutive cases. The intra-articular position of the femoral tunnel aperture was analyzed using the Magnussen classification.ResultsThe intra-articular tunnel position was deemed anatomical in 77%, intermediate in 20.8%, and non-anatomical in 2.2%. Among the mal-positioned tunnels, 54.8% were vertical, 29% were anteriorly positioned, and 16.1% were both.ConclusionsThe intra articular femoral tunnel aperture was well positioned using an outside-in technique. The main error of tunnel positioning was a tunnel too vertical.Level of Evidence: Level III, prospective study (case series).

Extra-articular procedures for the ACL-deficient knee: a state of the art review

Some patients have continued rotatory instability following intra-articular anterior cruciate ligament (ACL) reconstruction, which limits their functional abilities. Advanced surgical techniques, such as double-bundle reconstruction and anteromedial portal drilling, have not solved this problem. This has led many surgeons to revisit the use of extra-articular procedures to control rotatory laxity. Multiple anatomic studies have confirmed the presence of an anterolateral ligament (ALL) that attaches to the tibia at the site of the Segond fracture. The biomechanical importance of this ligament is still being debated. Extra-articular reconstructions decrease the forces produced by intra-articular ACL grafts. Patients likely to benefit from additional extra-articular reconstruction are: (1) those with high-grade pivot shifts; (2) patients with previous failed ACL reconstructions without an obvious cause; (3) participants in contact sports and (4) patients in subgroups that have a high risk of failure (eg, generalised laxity). A variety of extra-articular reconstructions have been developed. Those techniques that have long-term follow-up data were described before most current orthopaedic surgeons were in practice. The available evidence suggests that performing an additional extra-articular reconstruction can improve rotational stability in patients undergoing intra-articular ACL reconstructions. Newer ‘anatomic’ reconstructions of the ALL have recently been proposed but there are limited data on their effectiveness. Currently, there are no studies comparing different extra-articular procedures.

The anterolateral complex of the knee: results from the International ALC Consensus Group Meeting

The structure and function of the anterolateral complex (ALC) of the knee has created much controversy since the ‘re-discovery’ of the anterolateral ligament (ALL) and its proposed role in aiding control of anterolateral rotatory laxity in the anterior cruciate ligament (ACL) injured knee. A group of surgeons and researchers prominent in the field gathered to produce consensus as to the anatomy and biomechanical properties of the ALC. The evidence for and against utilisation of ALC reconstruction was also discussed, generating a number of consensus statements by following a modified Delphi process. Key points include that the ALC consists of the superficial and deep aspects of the iliotibial tract with its Kaplan fibre attachments on the distal femur, along with the ALL, a capsular structure within the anterolateral capsule. A number of structures attach to the area of the Segond fracture including the capsule-osseous layer of the iliotibial band, the ALL and the anterior arm of the short head of biceps, and hence it is not clear which is responsible for this lesion. The ALC functions to provide anterolateral rotatory stability as a secondary stabiliser to the ACL. Whilst biomechanical studies have shown that these structures play an important role in controlling stability at the time of ACL reconstruction, the optimal surgical procedure has not yet been defined clinically. Concern remains that these procedures may cause constraint of motion, yet no clinical studies have demonstrated an increased risk of osteoarthritis development. Furthermore, clinical evidence is currently lacking to support clear indications for lateral extra-articular procedures as an augmentation to ACL reconstruction. The resulting statements and scientific rationale aim to inform readers on the most current thinking and identify areas of needed basic science and clinical research to help improve patient outcomes following ACL injury and subsequent reconstruction.Level of evidence V.

Incidence and patterns of meniscal tears accompanying the anterior cruciate ligament injury: possible local and generalized risk factors

Aim of the workInjury to the anterior cruciate ligament (ACL) is frequently accompanied by tears of the menisci. Some of these tears occur at the time of injury, but others develop over time in the ACL-deficient knee. The aim of this study was to evaluate the effects of the patient characteristics, time from injury (TFI), and posterior tibial slope (PTS) on meniscal tear patterns. Our hypothesis was that meniscal tears would occur more frequently in ACL-deficient knees with increasing age, weight, TFI, PTS, and in male patients.MethodsOf the ACL-injured patients, 362 were analyzed, and details of meniscal lesions were collected. The medial and lateral tibial slopes (MTS, LTS) were measured via computed tomography. Patient demographics, TFI, MTS, and LTS were correlated with the diagnosed meniscal tears.ResultsOf the patients, 113 had a medial meniscus (MM) tear, 54 patients had a lateral meniscus (LM) tear, 34 patients had tears of both menisci, and 161 patients had no meniscal tear. The most common tear location was the posterior horn (PH) of the MM, followed by tear involving the whole MM. Patient age, BMI, and TFI were significantly associated with the incidence of MM tear. Female patients had a higher incidence of injury than males in all tear sites except in the body and PH. Male patients had more vertical and peripheral tears. The median MTS and LTS for patients with MM tears were 7.0°and 8.7°, respectively, while those of patients with LM tears were 6.9° and 8.1°. Steeper LTS was significantly associated with tears of LM and of both menisci.ConclusionOlder age, male sex, increased BMI, and prolonged TFI were significant factors for the development of MM tears. An increase in the tibial slope, especially of the lateral plateau, seems to increase the risk of tear of the LM and of both menisci.Level of evidence: Level III.

Valgus Knee: Severe Cases Included

Valgus deformity is less common than varus deformity in the arthritic knee, with an incidence of 10–15% in the population undergoing primary total knee arthroplasty (TKA) [1]. In cases of valgus knee, the surgeon uses the same set of instruments; however, the choice of approach, strategy for soft tissue balancing, order of ligament release, positioning of implants, and the degree of constraint required may vary considerably in comparison to the varus knee. These issues, as well as the management of bone defects caused by wear, must be considered during preoperative preparation and may require adaptation of the surgical plan according to the intraoperative situation. We emphasize the essential place of preoperative planning based on radiological and physical examination, which allows for staging of the deformity and choice of the proper surgical strategy.

Extra-articular Plasty with ACL Reconstruction: Long-Term Results of Associated Procedure

The aim of surgical management of the anterior cruciate ligament (ACL)-deficient knee is to restore knee stability, allowing return to activity and preventing secondary injury. Unfortunately, even in the face of technological advances in modern day ACL reconstruction, problems of persistent anterolateral rotational laxity exist. Recent research has therefore focused on the anterolateral structures and hence anterolateral reconstructions as a method to better control rotation. This paper provides an historical perspective on the use of lateral extra-articular reconstruction and where these procedures may be best utilised in todays ACL reconstruction algorithm.