The Knee

Contents List

2010-03-01

Editorial Board

2010-03-01

Synovial plicae around the knee

M. Kent, V. Khanduja — 2009-09-25

Abstract: Synovial plicae around the knee are a relatively common occurrence but one that is rarely responsible for symptoms. The Plica syndrome has been well described but controversy still exists regarding its diagnosis and treatment.We have reviewed and studied the published literature both past and present in detail regarding synovial plicae around the knee to provide a comprehensive and up-to-date review on the subject.The aim is to outline previous significant research into the embryology and pathology of synovial plicae as well as providing a review of the current thinking on treatment options available for the different synovial plicae with reference to the evidence available.

Arthroscopic resection of medial plica of the knee in young adults

2009-09-03

Abstract: The purpose of this study was to evaluate the long-term results of arthroscopic resection of a medial plica and to describe the usefulness of the clinical findings and MRI for preoperative diagnostics. From the baseline population of 172,777 military conscripts, thirty-three consecutive young adult patients with normal preoperative MRIs of the knee and a sole postoperative diagnosis of medial plica were treated with arthroscopic plica resection. Functional outcome was evaluated at a final follow-up in 25 patients with 34 knees with Kujala, Lysholm and visual analog scale (VAS) scores. Functional results were excellent to good in 17 patients, fair in three patients, and poor in 3 patients. The median Kujala score was 92 (25–100), the median Lysholm score 89 (26–100), and the median VAS 1.4 (0–8.8). Median follow-up time was 6.6 years (3.6–8.7 years). Most patients had no history of direct knee trauma preceding the symptoms. No statistically significant correlation was seen between MRI classification of the plica size or clinical findings compared to arthroscopic classification. Resection of the medial plica in a symptomatic knee has good to excellent functional long-term outcome in the majority of cases, and the procedure is not associated with postoperative complications. MRI and preoperative clinical examination seem to be unreliable in detecting medial plicae.

Synthetic grafts for anterior cruciate ligament rupture: 19-year outcome study

Alberto Ventura, Clara Terzaghi, Claudio Legnani, Enrico Borgo, Walter Albisetti — 2009-09-01

Abstract: Artificial ligaments for ACL replacement have been widely used in the 1980s and early 1990s in orthopaedic surgery. Synthetic devices have been utilized either as a prosthetic material or as an augmentation for a biological ACL graft substitute. The initial enthusiasm surrounding the introduction of synthetic graft materials stemmed from their lack of donor morbidity, their abundant supply and significant strength of these devices. The disadvantages in long-term follow-up were found to be cross-infections, immunological responses, tunnels osteolysis, femural and tibial fractures, foreign-body synovitis and knee osteoarthritis.A total of 126 patients were treated with artificial ACL substitution with polyethylene terephthalate (PET) synthetic ligaments in our Institute between 1986 and 1990. Of the original group, 51 sportsmen aged 15 to 40 were followed-up at a mean of 19years (range 17.5 to 20.6years) after surgery. Assessment was made with KOOS and IKDC score, Tegner activity scale, clinical examination, KT-1000 arthrometer, and X-ray evaluation.Of the 51 patients followed-up, 27.5% were found to have ruptured their PET ligaments and 100% presented degenerative osteoarthritis at the X-ray evaluation according to Ahlbäck radiological classification of arthritis. The objective evaluation showed functional impairment in 29.4% with an average reduction of 3 points in the Tegner activity scale.The osteoarthritis observed in all patients prompted us to avoid the diffusion of this surgical technique. Although in theory well-conceived, studies have yet to substantiate the function of these augmentation devices or to show clinical better results than those achieved with isolated autograft or allograft ACL substitutes.

Simultaneous anterior cruciate ligament reconstruction and opening wedge high tibial osteotomy: Report of four cases

Yasushi Akamatsu, Naoto Mitsugi, Naoya Taki, Ryohei Takeuchi, Tomoyuki Saito — 2009-06-29

Abstract: Four patients, aged 37–50 years, with chronic anterior cruciate ligament (ACL) deficiency, medial compartment osteoarthritis and varus deformity, underwent simultaneous arthroscopic ACL reconstruction and opening wedge high tibial osteotomy using the TomoFix fixation device and hydroxyapatite wedges. The simultaneous procedure allowed our patients to perform a full weight-bearing exercise at 4 weeks after surgery. At device removal and concomitant second-look arthroscopy, all patients had either a cyclops-like lesion or partial tears at the point of contact between the reconstructed ACL and intercondylar notch. Therefore, subsequent notchplasty or re-notchplasty was required.Because of the small number of patients, the results should be considered preliminary. Given our findings of graft morbidity caused by the corrected postoperative alignment, adequate intercondylar notchplasty should be performed at the initial operation.

Rehabilitation results following anterior cruciate ligament reconstruction using a hard brace compared to a fluid-filled soft brace

Hermann Otto Mayr, Alfred Hochrein, Werner Hein, Robert Hube, Anke Bernstein — 2009-08-17

Abstract: The purpose of this study was to compare the clinical outcomes of rehabilitation after ACL reconstruction using a water-filled soft brace to those using a hard brace.The method used in this study was a prospective randomised clinical trial including 36 patients wearing a hard brace and 37 patients wearing a water-filled soft brace for 6 weeks after surgery. Preoperative and postoperative (seven examinations) clinical evaluation within a follow-up period of 1 year including effusion status, swelling and range of motion (ROM), IKDC 2000, KT1000 Arthrometer™, Lysholm knee scoring scale and Tegner activity score. Mean values are presented with standard deviations. Data was analysed using descriptive statistics and Student's t-test for unpaired samples.Significantly less effusion was found in the soft brace group from 5 days (p=0.002) to 12 weeks (p<0.024) postoperative. Hard brace patients presented with significantly more extension deficit from 5 days (p=0.036) to 12 months (p=0.014) postoperative but no significant difference was detected in complete ROM, laxity or thigh atrophy at any follow-up examination. Patients treated with a soft brace had significantly higher IKDC subjective ratings at 6 weeks (p=0.02) up to 12 months after operation (p=0.002) and rated significantly higher in Tegner activity score (p=0.004) and Lysholm knee scoring scale (p=0.006) 6 and 12 months (p<0.001 for both scores) postoperatively.The water-filled soft brace was superior regarding effusion, swelling, extension deficit and patient-measured midterm outcome. The soft brace presents a safe, easy-to-use and effective alternative to the hard brace.

Sagittal knee joint kinematics and energetics in response to different landing heights and techniques

C.H. Yeow, P.V.S. Lee, J.C.H. Goh — 2009-09-01

Abstract: Single-leg and double-leg landing techniques are common athletic maneuvers typically performed from various landing heights during intensive sports activities. However, it is still unclear how the knee joint responds in terms of kinematics and energetics to the combined effects of different landing heights and techniques. We hypothesized that the knee displays greater flexion angles and angular velocities, joint power and work in response to the larger peak ground reaction force from 0.6-m height, compared to 0.3-m height. We further hypothesized that the knee exhibits elevated flexion angles and angular velocities, joint power and work during double-leg landing, relative to single-leg landing. Ground reaction force, knee joint kinematics and energetics data were obtained from 10 subjects performing single-leg and double-leg landing from 0.3-m to 0.6-m heights, using motion-capture system and force-plates. Higher peak ground reaction force (p<0.05) was observed during single-leg landing and/or at greater landing height. We found greater knee flexion angles and angular velocities (p<0.05) during double-leg landing and/or at greater landing height. Elevated knee joint power and work were noted (p<0.05) during double-leg landing and/or at greater landing height. The knee joint is able to respond more effectively in terms of kinematics and energetics to a larger landing impact from an elevated height during double-leg landing, compared to single-leg landing. This allows better shock absorption and thus minimizes the risk of sustaining lower extremity injuries.

The effect of patellar taping on patellar position measured using ultrasound scanning

Lee Herrington — 2009-09-01

Abstract: Previous research into the effect of patellar taping has found conflicting results and when studies have found positive findings these effects appear to be negated by exercise. The purpose of this study was to re-examine the effect of patellar taping on patellar position using ultrasound scanning. Twelve asymptomatic subjects (six males and six females (age 20.4+/−1.2 years)) had their patellar position examined, prior to and following the application of tape, and also following exercise (25 step ups). Mean patellar position (distance border patella to edge lateral femoral condyle) prior to application of tape was 6.2+/−1.3 mm following the application of tape mean patellar position was 7.9+/−1.7 mm, this was a statistically significant change in position (p=0.003). Following exercise mean patellar position was 7.6+/−1.7 mm this was a significant reduction compared to the taped position prior to exercise (p=0.001). This value was though still significantly greater than prior to the application of tape (p=0.006). This study found that patellar position was significantly changed following the application of tape. Furthermore, the study found that though low intensity exercise resulted in a significant change in the patellar position compared to the taped position prior to exercise, that change was most likely to have occurred due to random chance or measurement error.

A single measure of patellar kinematics is an inadequate surrogate marker for patterns of three-dimensional kinematics in healthy knees

E.J. McWalter, N.J. MacIntyre, J. Cibere, D.R. Wilson — 2009-09-01

Abstract: Patellofemoral disorders, such as osteoarthritis and patellofemoral pain, are thought to be associated with abnormal patellar kinematics. However, assessments of three-dimensional patellar kinematics are time consuming and expensive. The aim of this study was to determine whether a single static measure of three-dimensional patellar kinematics provides a surrogate marker for three-dimensional patellar kinematics over a range of flexion angles. We assessed three-dimensional patellar kinematics (flexion, tilt and spin; lateral, anterior and proximal translation) at sequential static angles through approximately 45° of loaded knee flexion in 40 normal subjects using a validated, MRI-based method. The surrogate marker was defined as the static measure at 30° of knee flexion and the pattern of kinematics was defined as the slope of the linear best fit line of each subject's kinematic data. A regression model was used to examine the relationship between the surrogate marker and pattern of kinematics. The surrogate marker predicted 26% of the variance in pattern of patellar flexion (p<0.001), 27% of the variance in pattern of patellar spin (p=0.003), 11% of the variance in pattern of proximal translation (p=0.037) and 39% of the variance in pattern of anterior translation (p<0.001). No relationships were seen between the surrogate marker and tilt or lateral translation. The results suggest that a single measure of patellar parameters at 30° knee flexion is an inadequate surrogate marker of three-dimensional patellar kinematics; therefore, a complete assessment of patellar kinematics, over a range of knee flexion angles, is preferable to adequately assess patterns of patellar kinematics.

Is a tourniquet beneficial in total knee replacement surgery? A meta-analysis and systematic review

Toby O. Smith, Caroline B. Hing — 2009-07-21

Abstract: Proponents of tourniquets postulate that they optimise intra-operative visibility and reduce blood loss. This study compared the outcomes of tourniquet assisted to non-tourniquet assisted total knee replacement (TKR). A systematic review was undertaken of the electronic databases Medline, CINAHL, AMED and EMBASE, in addition to a review of unpublished material and a hand search of pertinent orthopaedic journals. The evidence-base was critically appraised using a tool from the Cochrane Bone, Joint and Muscle Trauma Group. Fifteen studies were identified evaluating 16 outcome measures and parameters of 1040 TKRs in 991 patients. There was a significantly greater intra-operative blood loss in non-tourniquet compared to tourniquet assisted surgery (p=0.004). There was no significant difference between the groups for total blood loss or transfusion rate (p=0.22; p=0.48). There was a trend for greater complications in tourniquet compared to non-tourniquet patients. There was no difference between the groups for any other outcome measure assessed. In conclusion, this systematic review has found that there is no advantage to using a tourniquet in knee replacement surgery for reduction of transfusion requirements.

Measuring patellar height using the lateral active flexion radiograph: Effect of total knee implant design

Jean Brilhault, Michael D. Ries — 2009-09-01

Abstract: Patellar position during knee flexion was studied in 41 patients with bicruciate substituting (BCS), 41 patients with posterior cruciate retaining (CR) and 41 patients with posterior stabilized (PS) TKA's. The perpendicular height of the patella above the tibial tubercle was compared to the length of the patellar tendon on maximum flexion lateral radiographs. BCS knees had greater active flexion compared to PS and CR knees (BCS=124±9.8, PS=112±9.5, CR=110±10.9). In flexion, apparent patella infera (API) or the height of the patella above the tibial tubercle was 3.5% lower than the patellar tendon length for BCS knees, 1.7% lower in PS knees and 0.5% lower in CR knees. API in PS and BCS knees correlated with active knee flexion, but not in CR knees. Our findings indicate that an apparent inferior position of the patella occurs in BCS knees during deep flexion which is not caused by significant patellar ligament shortening or joint line elevation, but associated with normal posterior rollback of the femur.

Postoperative morbidity and mortality following total knee arthroplasty with computer navigation

James A. Browne, Chad Cook, Aaron A. Hofmann, Michael P. Bolognesi — 2009-09-16

Abstract: The incidence of postoperative complications following computer navigated total knee arthroplasty is unknown. There is no published evidence to support decreased morbidity compared to standard conventional technique. The Nationwide Inpatient Sample database was used to identify 101,596 patients who underwent total knee arthroplasty in 2005. Of these patients, 1156 were coded as having a computer-assisted procedure. Bivariate analysis and regression modeling were used to compare postoperative in-hospital outcomes between the computer-assisted and non-navigated cohorts. We found no differences in postoperative mortality or complications for the majority of our measured outcomes. Under multivariate regression analysis, computer navigation was associated with a lower rate of postoperative cardiac complications (odds ratio 0.40, p=0.042), a shorter length of stay, and a trend towards fewer hematomas. Further clinical study is required to examine the possible association of computer navigation with postoperative morbidity following knee arthroplasty.

Association of the calcitonin gene (CA) polymorphism with osteoarthritis of the knee in a Mexican mestizo population

2009-09-07

Abstract: Osteoarthritis (OA) is the most common form of destructive joint disease that is characterized by the degeneration of the articular cartilage, synovial membrane, joint capsule, and subchondral bone. The knee is a joint commonly affected for OA. Calcitonin (CT) has been suggested to have chondroprotective effects; therefore, could play a role in the pathogenesis of OA of the knee. Genetic variations in or adjacent to the CT gene may be associated with primary OA development. We conducted a case-control association study in which we examined the correlation between a dinucleotide (cytosine-adenine, CA) repeat polymorphism at the CT locus and OA of the knee in 88 patients with OA and in 111 control subjects from the Mexican mestizo population. Allele A and genotype AG frequencies were significantly higher in patients with OA than in control subjects (56.3 vs. 43.2%; p<0.001 and 40.9 vs. 26.1%; p=0.027, respectively), and were associated with the presence of OA of the knee (odds ratio [OR], 2.62; 95% confidence interval [95% CI], 1.30–5.27, and OR, 1.93; 95% CI, 1.04–3.58, respectively) using a logistic regression model adjusted for gender, age and Body mass index (BMI). The GG genotype was associated with a lower risk of OA development of the knee; thus, it may constitute a protective factor against this disease (OR, 0.40; 95% CI, 0.16–0.98).In summary, we conclude that the dinucleotide CA polymorphism in the CT gene may become a useful marker for genetic studies of OA of the knee in Mexican population.

Metabolic activity of osteoarthritic knees correlates with BMI

2009-09-03

Abstract: Osteoarthritis of the knee has consistently been linked to obesity, defined as a body mass index (BMI) >30kg/m2. It has been hypothesized that obesity may lead to osteoarthritis through increased joint pressure, accumulated microtrauma, and disruption of normal chondrocyte metabolism. These changes in chondrocyte metabolism have not been thoroughly investigated, and it is the purpose of this study to identify a relationship between BMI and altered chondrocyte metabolism in osteoarthritic tissue. Articular cartilage was harvested from the femoral condyles of patients after total knee arthroplasty, and analyzed in explant and alginate models. Glycosaminoglycan (GAG) content was measured using a dimethylmethylene blue assay and normalized to DNA content using a PicoGreen® assay. Studies have reported GAGs to be a reliable measurement of chondrocyte metabolism and osteoarthritis progression. Our results show a significant linear relationship of increasing BMI and increasing GAG content in both alginate and explant models (p<0.001 and p=0.001). Obese (BMI≥30kg/m2) and non-obese (BMI<30kg/m2) comparisons also demonstrated significant differences with higher GAG/DNA content in obese individuals compared to non-obese (p=0.001 and p=0.015). The study results reveal significant relationships between GAG content and BMI in this population of osteoarthritic patients. The significant difference in GAG content between the obese and non-obese patients supports the connection between osteoarthritis and obesity previously reported. Higher patient BMI (>30kg/m2) may be similar to dynamic compression injuries which cause increased GAG synthesis in response to cartilage damage.

Bicondylar spontaneous osteonecrosis of the knee: A case report

2009-07-21

Abstract: Spontaneous osteonecrosis of the knee was originally described as a distinct disorder in 1968. Characteristic imaging findings and distinctive demographic and clinical factors help distinguish this disease from other osteonecrotic conditions, with which it can be confused. This report presents a rare, atypical case of bicondylar spontaneous osteonecrosis of the knee in a young patient, and highlights the importance of a clear understanding of the clinical and radiographic characteristics of this condition to accurately diagnose and treat it when evaluating osteonecrotic lesions of the knee.

Osteochondritis dissecans of the patella in a XVII century player of the Florentine historic kickball

2009-09-03

Abstract: We report a case of osteochondritis dissecans in the patella of Francesco de' Medici, Prince of Capistrano, who lived from 1594 to 1614. He was known to play Florentine kick ball, a precursor of Rugby and American football, and speculate that trauma from this activity may have led to the lesion.

Arterial occlusion caused by a non-adsorbable bone graft after open wedge tibial osteotomy

Ralf Schäfer, Falk Mittag, Markus Wünschel — 2009-09-27

Abstract: We report a case of a near fatal complication of an open wedge high tibial osteotomy held by a Puddu plate. CT-scan and lysis therapy revealed a compression of the popliteal artery by the implanted hydroxyapatite wedge resulting in ischaemia of the lower limb. Revision surgery was performed and the prominent part of the wedge was removed, however two toes had to be amputated due to the initial tissue damage.

Mycobacterium fortuitum infection after anterior cruciate ligament reconstruction using a polylactic acid bioabsorbable screw: Case report

Horng Lii Oh, Darren B. Chen, Bradley G. Seeto, Samuel J. MacDessi — 2009-09-10

Abstract: We report a case of pretibial sinus and abscess after anterior cruciate ligament reconstruction using a polylactic acid tricalcium phosphate bioabsorbable screw for tibial fixation. Mycobacterium fortuitum was identified as the pathogen after specific mycobacterial cultures were obtained from operative specimens. M. fortuitum is a known but rare cause of periprosthetic infection. Diagnosis is often delayed as routine microbiological cultures do not utilise specific culture requirements for mycobacterial growth. There have been several reports in the literature of sterile abscesses associated with bioabsorbable screws. To our knowledge, this is the first case report of a non-tuberculous mycobacterial infection associated with a bioabsorbable implant. This case illustrates that post-operative Mycobacterium infection can occur as a complication of ACL reconstruction with bioabsorbable screw fixation and should be considered in the differential diagnosis of post-operative periprosthetic infection.

Corrigendum to “Childhood delayed septic arthritis of the knee caused by Serratia fonticola” [The Knee 16 (2009) 512–514]

2010-01-18

The authors regret that when this paper was published, the authors' names were displayed incorrectly. The correct names are now displayed above.

British Association for Surgery of the Knee

2010-03-01

Instructions for Authors

2010-03-01