Ronald P. Grelsamer

Patellofemoral arthroplasty: 2–12-year follow-up study

Seventy-two patellofemoral arthroplasties in 65 patients were followed an average of 4 years (range, 2-12 years). In 69 cases concomitant surgery was performed, including soft tissue realignments, tibial tubercle transfers, and unicompartmental femorotibial reconstructions. Twenty-two patients had already had knee procedures, 18 of which addressed their patellofemoral joint. The implant used in all cases features a deep, nonanatomic trochlear component. Using the Mansat scoring system, 85% of the results were good to excellent, with nearly 50% of these excellent. Fourteen complications were noted, seven related to the implant itself and seven associated with extrapatellar pathology. The authors have found patellofemoral arthroplasty to be a viable solution to end-stage patellofemoral arthritis, keeping in mind a nonforgiving surgical technique and the necessity to address all extraarticular pathology.

The Pathophysiology of Patellofemoral Arthritis

Faced with a patient suffering from patellofemoral arthritis, the surgeon must determine the pathophysiology of the condition, because different causes demand different treatments. Possible causes include malalignment, patellofemoral dysplasia, patellofemoral instability, patellofemoral trauma, obesity, osteoarthritis, inflammatory arthritis, and a genetic predisposition. Arthritis secondary to malalignment, dysplasia, instability, or trauma is less likely than arthritis secondary to the other causes to progress to femorotibial arthritis.

Prevalence of modifiable surgical site infection risk factors in hip and knee joint arthroplasty patients at an urban academic hospital.

Surgical site infections after hip and knee arthroplasty can be devastating if they lead to periprosthetic joint infection. We examined the prevalence of the modifiable risk factors for surgical site infection described by the American Academy of Orthopaedic Surgery Patient Safety Committee. Our study of 300 cases revealed that only 20% of all cases and 7% of revision cases for infection had no modifiable risk factors. The most common risk factors were obesity (46%), anemia (29%), malnutrition (26%), and diabetes (20%). Cases with obesity or diabetes were associated with all histories of remote orthopedic infection, 89% of urinary tract infections, and 72% of anemia cases. The high prevalence of several modifiable risk factors demonstrates that there are multiple opportunities for perioperative optimization of such comorbidities.

The patellofemoral syndrome; the same problem as the Loch Ness Monster?

Receiving a referral letter to see a patient with patellofemoral syndrome causes a feeling of heart-sink in most orthopaedic surgeons. It predicts an unhappy patient, a prolonged clinic appointment, and an unsatisfactory outcome. Especially as a reliable operation is an unlikely management outcome. Orthopaedic surgeons tend to be mechanically minded and see their main task as correcting abnormalities surgically. Patellofemoral syndrome is the antithesis of this. As Teitge said “patellofemoral syndrome: What does it mean? Historically a wastebasket term for pain and dysfunction ... patellofemoral syndrome is not a diagnosis but rather an admission of ignorance” [1]. A medical syndrome is a specific collection of signs, symptoms, laboratory results, and/or imaging findings that occur together often enough, so that the presence of one feature indicates the presence of the others. The causes of a syndrome can be investigated, as can its management and even its cure (consider hypermobility or complex regional pain syndromes). The term “patellofemoral syndrome” is widely used in the orthopaedic literature with many studies analysing patients labelled with this diagnosis. There aremany other terms used to pigeonhole these patients including patellofemoral pain syndrome and chondromalacia patellae [2]. The American Academy of Family Physician has stated that: “Patellofemoral pain syndrome can be defined as retropatellar or peripatellar pain resulting from physical and biochemical changes in the patellofemoral joint. It should be distinguished from chondromalacia, which is actual fraying and damage to the underlying patellar cartilage. Patients with patellofemoral pain syndrome have anterior knee pain that typically occurs with activity and often worsens when they are descending steps or hills. It can also be triggered by prolonged sitting. One or both knees can be affected. Consensus is lacking regarding the cause and treatment of the syndrome.” [3]. But is patellofemoral syndrome really a syndrome? A quick literature search of the term “patellofemoral syndrome” produced 17 recent papers reporting on patients with this problem [4–20]. With respect to the definition of the American Academy of Family Physicians all these papers included anterior knee pain, 11 included activities such as sports, walking or running, 13 included either descending stairs or hills (but none included both), and 14 included prolonged sitting. However 14 also included pain on squatting and kneeling. Furthermore 15 specifically excluded previous trauma. Four of the studies did not appear to fit the American Academy definition [4,10,17,18]. The Loch Ness Monster is a snake-like creature that is said to live in Loch Ness, a large lake in Scotland. Speculation about its existence has gone on for many years, much has been written about it, but it is almost certainly a myth. It is, however, fertile ground for argument and entertainment e.g. is it a surviving plesiosaur? Anterior knee pain is multi-factorial, and the cause of the pain can vary from patient to patient. Over the years, orthopaedic surgeons and physiotherapists

The intra- and inter-observer reliability of the physical examination methods used to assess patients with patellofemoral joint instability

BACKGROUND An accurate physical examination of patients with patellar instability is an important aspect of the diagnosis and treatment. While previous studies have assessed the diagnostic accuracy of such physical examination tests, little has been undertaken to assess the inter- and intra-tester reliability of such techniques. The purpose of this study was to determine the inter- and intra-tester reliability of the physical examination tests used for patients with patellar instability. METHODS Five patients (10 knees) with bilateral recurrent patellar instability were assessed by five members of the International Patellofemoral Study Group. Each surgeon assessed each patient twice using 18 reported physical examination tests. The inter- and intra-observer reliability was assessed using weighted Kappa statistics with 95% confidence intervals. RESULTS The findings of the study suggested that there were very poor inter-observer reliability for the majority of the physical tests, with only the assessments of patellofemoral crepitus, foot arch position and the J-sign presenting with fair to moderate agreement respectively. The intra-observer reliability indicated largely moderate to substantial agreement between the first and second tests performed by each assessor, with the greatest agreement seen for the assessment of tibial torsion, popliteal angle and the Bassetts sign. CONCLUSIONS For the common physical examination tests used in the management of patients with patellar instability inter-observer reliability is poor, while intra-observer reliability is moderate. Standardization of physical exam assessments and further study of these results among different clinicians and more divergent patient groups is indicated.

The Contribution of Different Femur Segments to Overall Femoral Torsion

Background: Femoral torsion is a critical parameter in hip and knee disorders. The unproven assumption is that the femoral neck exclusively contributes to the overall torsion of the femur. Purpose/Hypothesis: The aim of this study was to measure femoral torsion at different levels in patients with abnormally high or low femoral torsion and to compare the results with healthy volunteers. Our hypothesis was that the pattern of torsion distribution among the different femoral levels varies between patients with abnormal torsion and healthy volunteers. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Magnetic resonance images of patients with a history of patellar instability and torsion of the femur ≥25° (11 patients, 16 femurs) and ≤0° (14 patients, 22 femurs) were analyzed. Our controls were 30 healthy volunteers (60 femurs). To assess femoral torsion, 4 lines were drawn: a first line through the center of the femoral head and neck, a second line through the center of the femur at the top of the lesser trochanter, a third line tangent to the posterior aspect of the distal femur just above the attachment of the gastrocnemius, and a fourth line tangent to the posterior condyles. Three investigators performed the measurements; 1 performed the measurements twice. Results: All femur segments showed significantly different torsion among the high-torsion, low-torsion, and control groups. Regarding the pattern of torsion distribution, on average, all levels contributed to the torsion. The ratio between the average neck and shaft torsion shifted toward a higher value in the high-torsion group, mostly because of a lack of external torsion in the shaft, and toward a lower value in the low-torsion group, owing to both a lack of internal torsion of the neck and increased external torsion in the shaft. Conclusion: We established a difference between neck, mid, and distal femoral torsion with reproducible measurements. Our data suggest that all 3 levels of the femur contribute to the total femoral torsion, with a different pattern among patients with high torsion and patellar instability.

Patient-Specific Patellofemoral Arthroplasty

In the past few years, there has been renewed interest in patellofemoral arthroplasty. Although the results of off-the-shelf patellofemoral prostheses have varied, the researchers’ results with patient-specific patellofemoral arthroplasty are encouraging. Our experience shows that patient-specific patellofemoral arthroplasty is a safe and effective treatment option for patients who have isolated end-stage patellofemoral arthritis. The surgical technique for patientspecific patellofemoral arthroplasty is straightforward because positioning and alignment of the patient-specific trochlear prosthesis are determined preoperatively, thus eliminating intraoperative guesswork. This paper describes the technique of patellofemoral arthroplasty that incorporates a custom-designed patient-specific prosthesis for resurfacing of the patellofemoral trochlea.

Distal Femoral Varus Osteotomy for Osteoarthritis of the Knee

To The Editor: With regard to “Distal Femoral Varus Osteotomy for Osteoarthritis of the Knee” (2005;87:127-33), by Wang and Hsu, the authors should be congratulated on a series of technically well-executed osteotomies. However, because orthopaedists in training use this journal as a foundation for their education, I am concerned about the message that this paper delivers. Specifically, the authors appear to have violated the traditional principle that an osteotomy about the knee should be carried out on the side of the deformity. The penalty for this violation is usually an oblique joint line, persistent pain, and a challenging knee replacement. Figures 2-A, 2-B, and 2-C show the knee of a patient in whom the valgus deformity is secondary to an impressive deficit of the lateral plateau. The distal … Corresponding author: Jun-Wen Wang, MD Department of Orthopaedic Surgery Chang Gung Memorial Hospital at Kaohsiung 123 Ta Pei Road Niao Sung Hsiang, Kaohsiung Taiwan, Republic of China lee415{at}adm.cgmh.org.tw

Patellofemoral Resurfacing Arthroplasty in the Active Patient

Middle-aged patients with advanced isolated patellofemoral (PF) chondrosis/arthrosis want to remain active. Unfortunately, most of these individuals are not good candidates for realignment alone with or without cartilage restoration. Historically, these patients might have been considered candidates for patellectomy, but long-term follow-up has pointed out the morbidity of that procedure, which makes it an unacceptable option for these patients. Some arthroplasty proponents consider total knee replacement (TKA) as the “gold standard” for treating isolated PF arthritis. However, TKA changes the kinematics of the knee and often limits knee flexion, leaving many patients unable to remain as active as their partial knee replacement counterparts; moreover, TKA carries the risk of loosening for which the only solution remains a major revision. While patellofemoral resurfacing arthroplasty (PFA) has been available as long as TKA, it has a checkered past as a treatment for isolated PF arthritis. Fortunately, with newer generation implants and the recognition of the surgical technique’s unique features, many patients have very satisfactory outcomes. In those satisfied patients, activity recommendations must be based both on what the knee can do kinematically and on what the PFA will tolerate from a wear and loosening standpoint. With current material and implant methods, patients must be cautioned to minimize component overload, which may result in polyethylene (when present) wear and loosening; however, activities that maintain cardiopulmonary fitness and general conditioning can generally be allowed.

Patellofemoral Arthroplasty: Pearls and Pitfalls

There has been a proliferation of new patellofemoral implants, which reflects an increasing interest in this topic on the part of the orthopedic community. The procedure is a niche procedure reserved for patients with isolated patellofemoral arthritis who are unlikely to develop femorotibial arthritis in their lifetime, and for patients considered too young or too active to receive a total knee replacement. Other options include biological repair, tibial tuberosity transfers, patellectomy (partial or total), and total joint replacement surgery.