Publications

2009
The accuracy of magnetic resonance imaging scanning and its influence on management decisions in knee surgery: Galea A, Giuffre B, Dimmick S, Coolican MR, and Parker DA. (2009)"The accuracy of magnetic resonance imaging scanning and its influence on management decisions in knee surgery". The Journal of Arthroscopic and Related Surgery, May 2009; PURPOSE: The purpose of our study was to evaluate the impact of preoperative magnetic resonance imaging (MRI) assessment of articular knee pathology on the clinical management of patients presenting with joint line pain. METHODS: A preliminary study on 100 patients was performed to assess the accuracy of specific MRI sequences, using arthroscopy as a gold standard. Six hundred and eighteen consecutive patients with knee symptoms presenting to 2 specialist knee surgeons were then recruited. A clinical diagnosis of an arthroscopically treatable lesion was made in all cases. Clinical assessment data were correlated to subsequent MRI findings, recording any discrepancy and in particular whether or not MRI findings influenced management decisions. RESULTS: In the preliminary study, MRI sequences had an overall sensitivity of 83.2% and a specificity of 94.3% for the detection of chondral lesions. However, when considering arthroscopic grade III and IV lesions, MRI sensitivity and specificity were improved to 84.5% and 97.1%. In the second phase of the study, 141 (22.8%) of the 618 patients presenting with knee symptoms had an altered clinical management subsequent to MRI. The presence of unexpected chondral lesions was found in 77 of these patients. Conversely, 22 patients with clinical symptoms suspicious for simple chondral degeneration had unstable meniscal tears. CONCLUSIONS: We suggest that preoperative MRI scanning identifies a group of patients who have more advanced degenerative joint disease than the clinical assessment and the plain radiographs suggest. This would expedite definitive surgery in patients with advanced osteoarthritis on MRI scans. LEVEL OF EVIDENCE: Level II, development of diagnostic criteria on basis of consecutive patients with universally applied gold standard.; Read Abstract

2009
Patient expectations of hip and knee joint replacement surgery and postoperative health status: Cross, M., Lapsley, H., Barcenilla, A., Parker, D., Coolican, M., March, L (2009)"Patient expectations of hip and knee joint replacement surgery and postoperative health status". Clinical Orthopaedics and Related Research, Feb 2009; Objective To explore the relationship between preoperative patient expectations and postoperative health status in patients undergoing joint replacement surgery, with particular emphasis on the types of expectations held by patients. Methods Respondents completed the Hospital for Special Surgery (HSS) Hip/Knee Replacement Expectations Questionnaires pre-surgery, in addition to the Western Ontario and McMaster Osteoarthritis Index (WOMAC™) and the Short-Form 36-Item (SF-36) Health Survey and the Arthritis Self-Efficacy Scale. The WOMAC™ Index and SF-36 were also completed 3 and 6 months post-surgery. A total of 106 patients total hip replacement [THR]?=?28; total knee replacement [TKR]?=?78) completed questionnaires. No differences were seen in overall expectations between males and females or older or younger patients, although some differences between the age groups were seen for individual expectations on the HSS expectations questionnaires. For THR, a higher rating of the importance of expectations was correlated with a lesser improvement in pain from pre-surgery to 3 months post-surgery, whereas for TKR, a higher rating of expectations was associated with a greater improvement in function to 6 months post-surgery. Conclusions Patients have high expectations of surgery, which are correlated with post-surgery pain and function. Identifying the broad range of expectations may be helpful in preparation for surgery and gaining greater satisfaction with outcomes.; Read Abstract

2008
The Safety of Combined Usage of Local Anaesthetic Infiltration and Reinfusion Drains in Total Knee Arthroplasty: Parker DA, Coolican MR, Mather LE, Graham DA, DeWall MJ (2008)"The Safety of Combined Usage of Local Anaesthetic Infiltration and Reinfusion Drains in Total Knee Arthroplasty ". The Journal of Arthroplasty Aug 2008; Injection of local anesthetic during total knee arthroplasty (TKA) has been shown to aid postoperative pain relief. Reinfusion drains have also proven useful in decreasing allogenic blood transfusion. Combined use carries the risk of reinfusion of local anesthetic from drainage bag. We examined plasma ropivacaine concentrations from 20 patients undergoing TKA, who were treated with these 2 techniques. Samples were taken from a dedicated venous cannula and from the reinfusion drainage bag. The average amount of ropivacaine reinfused was 1.9 mg, a fraction of the injected dose (150 mg), and venous plasma concentrations reached peaks of 0.5 to 1.5 mug/mL, well below demonstrated levels of toxicity. Patients tolerated the treatment well, with no adverse outcomes. This study demonstrates the safety of combining these 2 techniques in TKA.; Read Abstract

2008
Isolated rupture of the lateral collateral ligament during yoga practice: a case report: Patel, S C, Parker, D A (2008)"Isolated rupture of the lateral collateral ligament during yoga practice: a case report". Journal of Orthopaedic Surgery, Dec 2008; We report a case of isolated rupture of the lateral collateral ligament (LCL) of the knee while attempting to place the left foot behind the head during yoga practice. The 34-year-old man had discomfort of the lateral aspect of the knee particularly with varus strain. A magnetic resonance image revealed rupture of the LCL at the insertion onto the fibula. The patient had grade-II laxity of the LCL and was treated non-operatively. At the 12-month follow-up, grade-I laxity of the LCL remained clinically evident, but function was not impaired.; Read Abstract

2008
Frontal Knee Alignment: Three-dimensional Marker Positions and Clinical Assessment.: Vanwanseele, B., Parker, D., Coolican, M. (2008) "Frontal Knee Alignment: Three-dimensional Marker Positions and Clinical Assessment". Clinical Orthopaedics and Related Research. epublished.; We assessed the validity of the hip-knee-ankle angle measured statically during three-dimensional (3-D) gait analysis and the tibial angle using an inclinometer compared with the mechanical axis on radiographs. Eleven individuals (20 knees) with radiographic knee osteoarthritis (OA) participated in this study. We determined the following: the lower-limb mechanical axis using weightbearing long-leg radiographs; hip-knee-ankle angle using the techniques of 3-D gait analysis in a static standing position; and tibial alignment using an inclinometer. The mean mechanical axis (+/- standard deviation) for this cohort was 0.7 degrees +/- 7.2 degrees (range, -13 degrees-16 degrees). The tibial alignment and hip-knee-ankle angle correlated with the mechanical axis but the correlation between the mechanical axis and the hip-knee-ankle angle was stronger. Our data suggest the inclinometer and 3-D gait analysis are valid ways to estimate mechanical alignment of the knee.; Read Abstract

2008
Costs and outcomes of total hip and knee joint replacement for rheumatoid arthritis.: March, L. M., A. L. Barcenilla, Cross, M.J., Lapsley, H.M., Parker, D., Brooks, P.M.(2008) "Costs and outcomes of total hip and knee joint replacement for rheumatoid arthritis". Clinical Rheumatology 27(10): 1235-1242.; The objective of the study was to ascertain costs and outcomes of total joint replacement surgery for rheumatoid arthritis(RA) in Australia from the patients' perspective and to explore whether costs were affected by health status pre- or postsurgery. RA patients, scheduled for primary unilateral total knee replacement (TKR) or total hip replacement (THR) surgery at five Sydney hospitals, were approached. Preoperatively, patients retrospectively recorded expenses incurred over the previous 3 months and the health assessment questionnaire (HAQ). Postoperatively, patients completed detailed prospective cost diaries, short form (SF) 36, and HAQ every 3 months during the first postoperative year. In addition, patients were asked to complete a visual analogue measure for pain at 12 months postsurgery. Arthritis-specific cost information included prescription and nonprescription medication, visits to health professionals, tests, special equipment, alterations to the house, and use of private or community services. Thirty-one TKR and 11 THR patients provided cost data for the first postoperative year. Out-of-pocket costs and service utilization decreased over the first postoperative year for both TKR and THR patients. In addition, there was an improvement in the health status as measured by SF-36 but not the HAQ at 3 and 12 months postoperatively. The small sample size of this analysis is reflective of the current national trends of RA joint replacement surgery. Despite the low incidence of RA joint replacement surgery, it was substantiated that patients consider the positive impact on health outcomes and costs important. The generic SF-36 detected improvements in the health status of these RA patients, while total HAQ scores failed to do so. HAQ was found to be insensitive in reflecting improvements following lower limb replacement surgery. Patient out-of-pocket costs significantly decreased postoperatively; however, these costs remain substantial compared to osteoarthritis total joint replacement patients.; Read Abstract

2008
Bone Bruises associated with ACL Rupture: Correlation with Injury Mechanism: Viskontas D, Giuffre BM, Duggal N, Graham DA, Coolican MRJ & Parker DA (2008)"Bone Bruises associated with ACL Rupture: Correlation with Injury Mechanism".AM J SPORTS MED, May 2008; BACKGROUND: Different patterns of bone bruising are seen on magnetic resonance imaging in acute anterior cruciate ligament ruptures. These patterns may relate to the mechanism of injury. HYPOTHESIS: There is a correlation between the mechanism of anterior cruciate ligament injury and bone bruise patterns on magnetic resonance imaging. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Data regarding the mechanism of anterior cruciate ligament rupture were collected prospectively on patients who had anterior cruciate ligament reconstructions. Inclusion criteria included a clear history of mechanism, magnetic resonance imaging within 6 weeks of injury, and no previous knee injury. Patients were divided into noncontact and contact mechanism groups. Bone bruise frequency, location, depth, and intensity were analyzed using magnetic resonance imaging and correlated with the mechanism of injury. RESULTS: Two hundred fifty-six patients were identified; 100 met the inclusion criteria, 86 were in the noncontact mechanism group, and 14 were in the contact mechanism group. The proportion of bone bruises in the lateral compartment in both groups was higher (P < .001) than in the medial compartment. Bone bruising was more frequent, deeper, and more intense in the noncontact group, with frequency (P = .019) and intensity (P < .001) scores reaching significance at the lateral tibial plateau. Medial compartment bone bruising was seen more frequently than previously reported, particularly in the noncontact group. CONCLUSION: The noncontact mechanism appears to cause more severe bone bruising in both the medial and lateral compartments.; Read Abstract

2008
Reliability of bony landmarks for restoration of the joint line in revision knee arthroplasty.: Servien E, Viskontas D, Giuffrè BM, Coolican MR, Parker DA. (2008)"Reliability of bony landmarks for restoration of the joint line in revision knee arthroplasty."Knee Surg Sports Traumatol Arthrosc. Mar 2008; The aim of this study was to determine the reliability of bone landmarks for restoring the joint line in revision knee arthroplasty. The relationship of the femoral epicondyles, the tibial tubercle (TT) and the fibular head (FH) to the joint line was measured on 200 magnetic resonance imaging (MRI, 100 females, 100 males), including assessment on intraobserver and interobserver reliability. MRI scans demonstrating chondral lesions and osteoarthritis were excluded, as were patients with immature skeletons or a history of previous knee surgery. Sequences in sagittal, coronal and axial planes were used as well as cross-referencing with the same computer software. In order to account for size differences between patients, each bony landmark measurement was converted to a ratio relative to the femoral or/and tibial width. We found a transepicondylar axis equal to 3.11 degrees (+/-1.9). The average distance from the epicondyles to the joint line was respectively 23 mm on the lateral side and 28 mm on the medial side. However there was a variation of distance from the epicondyles of the joint line up to 11 mm and a significative difference was found between male and female. We determined the distances from the tip of the FH and from the TT to the joint line. The joint line-FH distance averaged 14 mm (range 4.1-22.13) with no gender difference. The joint line-TT distance was averaged 22 mm (range 10.61-32.09). We determined an epicondylar ratio (distance from the lateral epicondyle to the joint line related to the femoral width). We found this ratio averaged 28% with no gender difference (P = 0.09). There is a large variation of bony landmarks depending on the size of the individual. Considering this findings, the FH is not a reliable guide for the joint line in revision surgery. Previous studies have measured the absolute values from various landmarks to the joint line. This study provides a significant advantage, in that the level of the joint line can be determined for each individual by using a ratio to account for gender and size differences.; Read Abstract

2007
Osteotomy for the Early Varus Arthritic Knee.: Parker DA, Viskontas D (2007)"Osteotomy for the Early Varus Arthritic Knee". Sports Medicine and Arthroscopy Review, Mar 2007; High tibial osteotomy is a well-established procedure for the management of medial compartment arthritis that is currently experiencing a resurgence in popularity. A number of techniques have been described, with the ultimate goal of obtaining appropriate alignment to provide pain relief and functional improvement over a long-term period. Appropriate patient selection and careful surgical technique is necessary to achieve these goals with a minimal risk of complication. Newer technology such as computer navigation promises to improve the overall accuracy of the procedure. The need for alignment correction in combination with ligament reconstruction and chondral resurfacing surgery will increase the indications for this procedure. This article discusses the techniques available for high tibial osteotomy, the results and relative advantages of each, and the appropriate surgical technique to achieve optimal results while minimizing complications.; Read Abstract

2007
Posterior cruciate ligament deficiency: Biomechanical and biological consequences and the outcomes of conservative treatment: A systematic review.: Grassmayr, M.J., Parker, D.A., Coolican, M.R.J., Vanwanseele, B. (2007)"Posterior cruciate ligament deficiency: Biomechanical and biological consequences and the outcomes of conservative treatment: A systematic review". Journal of Science and Medicine in Sport, 18, 2007; The objective of the study was to evaluate the biomechanical and biological consequences of posterior cruciate ligament deficiency, determine compensatory mechanisms and assess the efficacy of non-operative treatment. Medline, CINAHL, SPORT discus, Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews were searched at 30th October 2006 for the terms "PCL" and "posterior cruciate ligament" both independently and including the terms "injury", "deficiency" and "insufficiency". Literature searches identified 598 potentially relevant articles, after exclusions there were 47 articles that fulfilled the inclusion criteria: 30 articles analyzing PCL deficiency and 17 studies on the outcomes for non-operative treatment. The authors reviewed all selected articles and abstracted data into predetermined tables depending upon classification. Studies indicate that posterior cruciate ligament deficiency results in posterior tibial translation with combined injuries displaying greater laxity. Results were inconsistent for rotational stability but deficiency increases joint contact pressure and may result in articular damage. A loss of proprioception occurs but the effect on strength and kinetics is inconclusive. There is a lack of evidence for compensatory muscle activity. Return to activity is possible for the majority of non-operatively treated grade I and II isolated injuries. Comparative analysis was not possible in many instances due to study design or experimental protocols. Further research is required to establish the compensatory mechanisms stabilizing the posterior cruciate ligament deficient knee and to investigate the outcomes for non-operatively treated patients.; Read Abstract

2006
Complex regional pain syndrome complicating total knee arthroplasty: Burns, A. W. R., Parker, D. A., Coolican, M. R. J. and Rajaratnam, K. (2006). "Complex regional pain syndrome complicating total knee arthroplasty". Journal of Orthopaedic Surgery 14(3): 280.; To compare the long-term outcome of patients diagnosed with complex regional pain syndrome-type 1 (CRPS-1) after total knee arthroplasty (TKA) with those of uncomplicated TKA knees and preoperative osteoarthritic knees. Medical records of 1280 patients who underwent TKA for osteoarthritis were retrospectively reviewed; 8 were diagnosed as having symptoms and signs consistent with CRPS after TKA. Patients with primary inflammatory arthritis, signs of component loosening, malpositioning, or of infected arthroplasty were excluded. No patient had signs of CRPS prior to operative intervention. The 8 patients were compared with 2 groups of age- and sex-matched controls: uncomplicated TKA knees and preoperative osteoarthritic knees. Patients were followed up for a mean of 54 (range, 13-111) months and their range of movement, Western Ontario and McMaster Universities Osteoarthritis Index, SF-36 questionnaire scores, and Knee Society scores were assessed and compared. After appropriate treatment, most CRPS complicated patients had similar scores on SF-36, Western Ontario and McMaster Universities Osteoarthritis Index, and Knee Society scores when compared with uncomplicated TKA patients. Scores for CRPS complicated patients were significantly improved when compared with preoperative osteoarthritic patients. The incidence of CRPS after TKA was 0.7%. When managed early, patients complicated with CRPS after TKA have a similar prognosis to patients with uncomplicated TKA.; Read Abstract

2005
Spinal cord injuries in Australian footballers 1997-2002: Carmody, D. J., Taylor, T. K., Parker, D. A., Coolican, M. R. and Cumming, R. G. (2005). "Spinal cord injuries in Australian footballers 1997-2002." Medical Journal of Australia 182(11): 561.; OBJECTIVE: To review acute spinal cord injuries (ASCIs) in all Australian codes of football (rugby union [RU], rugby league [RL], Australian Rules football [ARF] and soccer) for 1997-2002 and to compare data with those of a 1986-1996 survey. DESIGN: Retrospective review of hospital records, and structured interviews with injured players. PARTICIPANTS AND SETTING: Patients admitted to any of the six Australian spinal cord injury units with a documented football-related ASCI over the period 1997-2002. OUTCOME MEASURES: Average annual incidence of ASCIs per 100,000 players in the different codes, final Frankel grading of injuries, and wheelchair status. RESULTS: Fifty-two footballers (45 adult men and seven schoolboys) suffered ASCIs between 1997 and 2002. The average annual incidence of ASCIs per 100,000 players was 3.2 for RU, 1.5 for RL, 0.5 for ARF and 0.2 for soccer. While there has been little change in incidence since the 1986-1996 survey, there has been a trend towards less severe injuries in RU and RL, but not in ARF. There have been no scrum injuries in RL since 1996, when the scrum stopped being contested. Seven injuries occurred in RU scrums, six at the moment of engagement of the opposing teams. The incidence of 2-on-1 and "gang" tackles (involving multiple tacklers) in RL is disturbing. Overall, 39% of injured players became permanently wheelchair-dependent. CONCLUSIONS: There continues to be good reason to revise the laws of scrum engagement in RU. The laws relating to multiple tacklers in RL should be examined. The insurance cover for injured players is grossly inadequate. The longstanding need for a registry of spinal cord injuries for all football codes regrettably remains unmet.; Read Abstract

2004
Medial compartmental knee arthroplasty with the Miller-Galante prosthesis: Naudie, D., Guerin, J., Parker, D. A., Bourne, R. and Rorabeck, H. (2004). "Medial compartmental knee arthroplasty with the Miller-Galante prosthesis." Journal of Bone and Joint Surgery 86: 1931-1935.; Unicompartmental knee arthroplasty has become a popular treatment alternative for osteoarthritis that is confined to the medial part of the knee. Excellent intermediate-term results recently have been reported in assosciation with the Miller-Galante unicompartmental implant. The purpose of the present study was to report on out longer-term experience with the Miller-Galante unicompartmental knee replacement. Methods: We evaluated the results of 113 medial unicompartmental knee arthroplasties that had been performed with the use of the Miller-Galante implant in 84 patients between 1989 and 2000. The mean age of the patients at the time of surgery was 68 years. Forty-five patients were men and thirty-nine were women. Thirteen patients (sixteen knees) died at a mean of seven years after the index arthroplasty. No patient was lost to follow-up. The remaining seventy-one patients (ninety-seven knees) were followed for a mean of ten years and were evaluated with use of the Knee Society Clinical Rating System. Results: Eleven knees were revised at a mean of four years after the index procedure. The mean Knee Society and function scores for the sixty-one patients (eighty-six knees) who were living and had not had a revision improved from 48 and 53 points preoperatively to 93 and 80 points at the time of the most recent evaluation. The five and ten year rates of survival were 94% and 90% respectively, with revision to tricompartmental knee arthroplasty as the end point and 93% and 86%, respectively, with revision or radiographic loosening as the endpoint. Conclusions: The Miller-Galante medial unicompartmental knee arthroplasty provided excellent pain relief and restoration of function in carefully selected patients and demonstrated durable implant survival at ten years.; Read Abstract

2003
Extensor Mechanism Failure Associated With Total Knee Arthroplasty: Prevention and Management: Parker, D. A., Dunbar, M. J. and Rorabeck, C. H. (2003). "Extensor Mechanism Failure Associated With Total Knee Arthroplasty: Prevention and Management." Journal of the American Acadamy of Orthopedic Surgeons 11(4): 238-247.; Extensor mechanism complications are the most commonly reported reasons for revision surgery after total knee arthroplasty and are a frequent source of postoperative morbidity. Patellofemoral instability is the most commonly reported extensor mechanism complication and has multiple etiologies, including prosthetic malalignment and soft tissue imbalance. Patellar fracture or rupture of either the quadriceps or patellar tendon can cause catastrophic disruption of the extensor mechanism. Although some stable fractures can be successfully managed nonsurgically, displaced fractures or tendon rupture often lead to poor results. Other complications include patellar clunk and soft-tissue adhesions, prosthetic wear or loosening, and osteonecrosis. Increased understanding of implant alignment, rotation, and soft-tissue balance, as well as improved design of the trochlear groove of femoral implants and patellar components, has resulted in a decline in extensor mechanism complications. Appropriate prosthetic selection and meticulous surgical technique remain the keys to avoiding unsatisfactory results and revision surgery.; Read Abstract