Treatment Of Patellofemoral Osteoarthritis Research Articles

Poster 300: A Novel Magnetic Resonance Imaging (MRI) Scoring System to Evaluate Patellofemoral Osteoarthritis

Objectives: Knee osteoarthritis (OA) is a common degenerative or post-traumatic condition, and may affect one or more compartments, including the medial and lateral tibiofemoral or patellofemoral articulations. Isolated patellofemoral osteoarthritis (PFOA) has been reported in 24% of women and 11% of men aged > 55 years presenting for evaluation of knee pain. PFOA is a result of abnormal mechanical loading across the patellofemoral joint, often related to prior instability, trauma, malalignment or post- surgical changes. Treatment of PFOA typically includes a trial of conservative management, including physical therapy, injections and activity modification. Operative treatment involves joint preservation (i.e., cartilage restoration procedures, tibial tubercle osteotomy, or lateral lengthening) and joint replacement (patellofemoral arthroplasty) procedures. In contrast to the tibiofemoral compartments, the current literature lacks a reliable magnetic resonance imaging (MRI) scoring system to quantitatively evaluate patellofemoral cartilage degeneration. The present study aims to describe, apply and assess the inter-observer reliability of a novel MRI scoring system for assessment of the patellofemoral cartilage. Methods: We conducted a query of an institutional database to identify all patients who underwent patellofemoral arthroplasty by the senior surgeon (S.M.S.) between January 2012 and December 2021. Patients with poor quality or lacking preoperative knee MRI were excluded. MRI scans were performed on 1.5 or 3.0-Tesla magnets utilizing dedicated extremity coils and standardized clinical imaging protocols consistent with International Cartilage Regeneration and Joint Preservation Society (ICRS) guidelines for the assessment of articular cartilage. Preoperative MRI scans were reviewed and patellofemoral cartilage was scored by a fellowship-trained musculoskeletal radiologist and a fellowship- trained orthopedic knee surgeon using our novel MRI scoring system. The novel semi-quantitative MRI patellofemoral scoring system includes assessment of patellar and trochlear cartilage, bony architecture, patellofemoral alignment, and synovitis (Table 1). For statistical analysis, inter-observer agreement was assessed using Cohen-Kappa coefficient for categorical variables, and intraclass correlation coefficient (ICC) for the total score. The measurement agreement for reach variable and total score was interpreted according to the Landis and Koch criteria: 0 - 0.2, slight; 0.21 - 0.4, fair; 0.41 - 0.6, moderate; 0.61 - 0.80, substantial; 0.81 - 1.0, almost perfect. Results: A total of 72 patients were included in the final analysis. The mean (± standard deviation) age and body mass index (BMI) of all patients was 53.30±7.72 years and 27.3±5.37 kg/m, respectively. Patellar bone edema and patellar cysts demonstrated moderate inter-observer agreement. All cartilage features, trochlear bone edema and cysts, osteophytes, subchondral remodeling, patellar height, and synovitis demonstrated substantial inter-observer agreement. Patellofemoral alignment and total score demonstrated almost perfect inter-observer agreement (Table 2 and Figure 1). Conclusions: The novel MRI scoring system for PFOA proposed by the authors is an attempt to develop a comprehensive method to assess patellofemoral joint cartilage degeneration, including evaluation of patellar and trochlear cartilage changes, bony architecture, patellofemoral alignment, and synovitis. Importantly, all features of the scoring system demonstrated at least moderate inter-observer agreement, with the majority of variables and total score demonstrating substantial to near perfect agreement. Future studies should aim to validate this scoring system in patients with and without patellofemoral arthritis and attempt to correlate scores with clinical outcomes. [Table: see text][Table: see text]

Arthroscopic Debridement, Facetectomy, and Synovectomy for Isolated Patellofemoral Osteoarthritis

Isolated patellofemoral osteoarthritis (PFOA) is a condition that affects climbing, squatting, and standing up movements in daily life and sports. Various surgical methods have been developed to address the various causes, different degrees of cartilage degeneration, and combined lesions. We describe an arthroscopic patellofemoral arthroplasty technique, with the main purpose to decrease the pain originating from the patellofemoral joint and related structures. The critical points of this technique are patellofemoral denervation and partial patellar facetectomy. Our clinical experience indicates that this technique is effective to address all kinds of PFOA. We consider that the introduction of this technique will provide a feasible choice when surgical treatment of PFOA is indicated.

Expert consensus on surgical treatment of patellofemoral osteoarthritis

Patellofemoral osteoarthritis (PFOA) is one of the most common causes of anterior knee pain in middle-aged and elderly population. In general, elementary therapy and drug therapy are the preferred choices for PFOA management. However, for those who cannot achieve satisfactory effectiveness with standard non-surgical treatment, surgical therapy stands as an alternative treatment. The surgical therapy includes repair surgery and reconstruction surgery. The choice of surgical plans for PFOA management mainly depends on the etiology, pathogenesis, location, and severity of the lesions. To aid clinical decision-making, the National Clinical Research Center for Geriatric Disorders (Xiangya Hospital) and the Joint Surgery Branch of the Chinese Orthopedic Association arranged nationwide orthopedic specialists to set up a work panel. After reviewing the research progress of surgical therapy and the latest guidelines and consensus for PFOA management, the work panel discussed repeatedly to reach this consensus. The present consensus aims to provide valid evidences for clinical practices of the surgical therapy of PFOA, so as to avoid inappropriate and irregular treatment behaviors, reduce surgical trauma, improve surgical efficacy and the quality of life, and to ease the burden of PFOA.

Medical Interventions for Patellofemoral Pain and Patellofemoral Osteoarthritis: A Systematic Review.

Patellofemoral pain (PFP) and patellofemoral osteoarthritis (PFOA) are common, persistent conditions that may lie along a pathological spectrum. While evidence supports exercise-therapy as a core treatment for PFP and PFOA, primary care physicians commonly prescribe medication, or refer for surgical consults in persistent cases. We conducted a systematic review of medical interventions (pharmaceutical, nutraceutical, and surgical) for PFP and PFOA to inform primary care decision making. Methods: Following protocol registration, we searched seven databases for randomized clinical trials of our target interventions for PFP and PFOA. Our primary outcome was pain. We assessed risk of bias, calculated standardized mean differences (SMDs) and determined the level of evidence for each intervention. Results: We included 14 publications investigating pharmaceutical or nutraceutical interventions, and eight publications investigating surgical interventions. Two randomized control trials (RCTs) provided moderate evidence of patellofemoral arthroplasty having similar pain outcomes compared to total knee arthroplasty in isolated PFOA, with SMDs ranging from −0.3 (95% CI −0.8, 0.2, Western Ontario McMaster Pain Subscale, 1 year post-surgery) to 0.3 (−0.1, 0.7, SF-36 Bodily Pain, 2 years post-surgery). Remaining studies provided, at most, limited evidence. No efficacy was demonstrated for oral nonsteroidal anti-inflammatories or arthroscopic surgery. Conclusions: Pharmaceutical and nutraceutical prescriptions, and surgical referrals are currently being made with little supporting evidence, with some interventions showing limited efficacy. This should be considered within the broader context of evidence supporting exercise-therapy as a core treatment for PFP and PFOA.

Partial lateral patellar facetectomy combined with lateral retinaculum release for treatment of patellofemoral osteoarthritis

Objective To evaluate the clinical outcomes of partial lateral patellar facetectomy (PLPF) combined with lateral retinaculum release (LRR) for treatment of patellofemoral osteoarthritis (PFOA). Methods From June 2017 to March 2018, 30 PFOA patients underwent PLPF combined with LRR at Department of Orthopedics and Traumatology, Foshan Hospital of Traditional Chinese Medicine. They were 7 men and 23 women with an average age of 56.4±9.7 years. Their patellar position, patellofemoral joint function, overall knee function, and quality of life were assessed by comparing preoperation and last follow-up in patellofemoral congruence angle (PFCA), lateral patellofemoral angle (LPFA), modified Kujala score, The Western Ontario and Mcmaster Universities Osteoarthritis Index (WOMAC), and SF-12 quality of life scale. Results All the patients were followed up for an average of 7.6±3.4 months (from 4 to 13 months). The PFCA was improved from preoperative 22.9°±7.6° to 12.4°±4.2° at the last follow-up, the LPFA from preoperative 3.2°±3.7° to 12.9°±6.0° at the last follow-up, the modified Kujala score from preoperative 17.1±9.8 to 34.3±5.7 at the last follow-up, the WOMAC from preoperative 14.1±5.2 to 5.9±1.7 at the last follow-up, the stiffness index from preoperative 5.5±3.2 to 2.7±1.2 at the last follow-up, daily functional index from preoperative 43.9±9.0 to 25.2±5.4 at the last follow-up, and the SF-12 scores from preoperative 31.3±5.2 to 55.7±6.0 at the last follow-up. All the above comparisons showed a significant difference (P<0.05). Conclusion PLPF combined with LRR is a minimally invasive, easy-to-master and effective knee joint preserving procedure for PFOA as it can significantly relieve joint pain and maximally keep patellar functions. Key words: Osteoarthritis, knee; Arthroplasty; Surgical procedures, minimally invasive; Lateral retinaculum release; Knee joint preserving procedure

Histopathological changes in the infrapatellar fat pad in an experimental rabbit model of early patellofemoral osteoarthritis

BackgroundThe purpose of this study was to characterise the histopathological changes in the infrapatellar fat pad (IPFP) in the early stage of patellofemoral osteoarthritis (PFOA). MethodsSixty-four New Zealand white rabbits were randomly divided into experimental (n = 24), sham (n = 16), and control groups (n = 24). In the experimental group, denoted as the patellar ligament uneven shortening group (US group), the patellar ligament (PL) was folded eight millimetres and sutured. After eight weeks, all animals were euthanised, and magnetic resonance imaging (MRI) evaluation, wet IPFP weight measurement, and histopathological and immunohistochemistry analysis were performed to analyse the histopathological changes in the IPFPs. ResultsThe maximum cross-sectional area (CSA) of the IPFPs in the sagittal position of MRI in the control group, sham group, and US group were 45.50 ± 7.19 mm2, 45.88 ± 6.60 mm2 (vs. control group, P = 0.907), and 53.83 ± 8.24 mm2 (vs. control group, P = 0.015; vs. sham group, P = 0.035), respectively. The MRI intensity of the IPFPs in the control group, sham group, and US group were 115.53 ± 28.85, 108.53 ± 26.73 (vs. control group, P = 0.589), and 154.52 ± 18.48 (vs. control group, P = 0.002; vs. sham group, P = 0.002), respectively. The wet weight of the IPFPs in the control group, sham group, and US group were 0.32 ± 0.05 g, 0.32 ± 0.04 g (vs. control group, P = 0.895), and 0.38 ± 0.06 g (vs. control group, P = 0.017; vs. sham group, P = 0.033), respectively. The Osteoarthritis Research Society International (OARSI) scores of the IPFPs in the US group were 6.00 ± 1.91, which was higher than the scores of 2.50 ± 2.02 (P < 0.001) in the control group and of 2.75 ± 1.67 (P = 0.001) in the sham group. ConclusionsThe histopathological changes of the IPFPs as determined via MRI and microscopic structure appeared to occur much earlier than cartilage damage in PFOA. Furthermore, detecting and treating the IPFP changes may offer aid in the diagnosis and treatment of PFOA.

Is the effectiveness of patellofemoral bracing modified by patellofemoral alignment and trochlear morphology?

BackgroundThis study was performed to determine if the effectiveness of patellofemoral bracing as a treatment for patellofemoral osteoarthritis is influenced by patellofemoral joint alignment and trochlear morphology. We hypothesized that those with more extreme patellar malalignment would benefit more from bracing.MethodsThirty-eight patients who had received bracing as part of a comprehensive treatment plan for patellofemoral osteoarthritis were selected for this study. Ten measures of patellar alignment were taken from X-rays. These alignment measures were divided into percentile groups (tertiles) for contingency table analysis. Treatment outcome was measured by Western Ontario and Macmasters Universities Osteoarthritis Index (WOMAC) scores and these were dichotomised into two groups according to “Improved” or “Not Improved” according to the minimum clinically important difference (MCID). Spearman’s rho test was performed for continuous variables and Fisher’s exact test was performed for correlation between tertile groups and MCID categories.ResultsThirty-eight patients (9 male and 29 female) between the ages of 51 to 89 were included in this study. WOMAC scores ranged from −25 to 41.67, with a mean change of −3.97, 31.6, 44.7 and 31.6% of patients falling into the “Improved” group for Global, Pain and Function scores respectively. We found a non-significant trend shown (p = 0.058, correlation coefficient 0.31) between bisect offset and change in WOMAC global, indicating a trend for higher change in WOMAC scores with increasing bisect offset. Statistically significant correlations were found between mean MCID categories for the WOMAC global and function groups when analysed against percentile groups for bisect offset (p < 0.01) and patellar subluxation distance (p < 0.05), indicating those in higher percentile groups were more likely not to improve after six months.ConclusionHigher bisect offset and patellar subluxation distance measures were associated with poorer outcomes. However, due to the limited sample size, more studies are required to fully examine this relationship.

Patellofemoral joint arthroplasty

Isolated patellofemoral osteoarthritis (PFOA) is symptomatic in around 10% of people aged over 55 years. This article presents a review of the treatment of PFOA with isolated patellofemoral arthroplasty (PFA). PFA has evolved in patient selection, surgical technique and implant design since its inception in the 1950s. Despite good clinical outcomes and survivorship being reported in the literature from a number of implants, PFA still remains a controversial subject due to high revision rates reported from large registries such as the National Joint Registry (NJR). Whilst patient selection and intra-operative techniques to optimize extensor mechanism function and avoid dynamic ‘overstuffing’ of the patellofemoral joint are key to the success of PFA, they are often overlooked. More recently, concomitant procedures to address patellar instability, tibiofemoral malalignment and patellofemoral malalignment have been performed to optimize PFA outcomes. With attention to detail in patient selection and surgical technique, using appropriate implants, PFA can lead to improved clinical outcomes and high survivorship for the treatment of isolated severe PFOA.

Treatment of patellofemoral osteoarthritis with patello-femoral joint arthroplasty

To study the outcome and surgical technique of patello-femoral joint arthroplasty (PFJ) for osteoarthritis of the knee. From January 2010 to June 2012, 17 patients (24 knees) with patello-femoral compartmental osteoarthritis treated by PFJ were reviewed retrospectively. There were 2 male patients (4 knees) and 15 female patients (15 knees), with an average age of (64 ± 9) years (52-77 years) . The mean body mass index was (24 ± 3) kg/m² (18.0-30.1 kg/m²) . Patients were asked to return for follow-up examinations at 3, 6 months and at every year after PFJ. The range of motion (ROM), visual analogue scale(VAS), Hospital for Special Surgery score (HSS score) , Feller patella score, quadriceps muscle strength were evaluated before and after PFJ. The paired sample t-test and one-way analysis of variance (ANOVA) with replicate measures were used to determine whether there were statistically significant differences between the mean data. All of the patients were followed up for 18-47 months, with a mean time of (29 ± 10) months, 75.0% patients were satisfied with the outcome of this surgical procedure 1 year postoperative, and 87.5% were satisfied 2 years postoperative. HSS score was increased from 61 ± 11 to 90 ± 6 at the final follow-up (t = 12.24, P = 0.000). VAS score was reduced from 6.7 ± 1.0 to 2.4 ± 1.0 (t = 15.84, P = 0.000). The mean post-operative ROM of the knees was 126° ± 7° (t = 3.25, P = 0.003). Feller patella scores were 18.0 ± 3.2 before operation, and 18.5 ± 4.5, 19.7 ± 3.4, 24.0 ± 3.8, 26.0 ± 3.3, 26.6 ± 2.5 at 3, 6, 12, 24 months after operation, final follow-up, respectively. Quadriceps muscle strength were 3.9 ± 0.5 before operation, and 3.7 ± 0.5, 3.9 ± 0.5, 4.2 ± 0.5, 4.3 ± 0.5, 4.3 ± 0.5 at 3, 6, 12, 24 months after operation, final follow-up, respectively. Repeated measures ANOVA found significant time effects for Feller patella scores (F = 38.97, P = 0.000) and quadriceps muscle (F = 6.89, P = 0.000). Feller patella scores and quadriceps muscle strength were low at 3, 6 months after operation, with no significant differences compared with pre-operation data (P > 0.05). The improvements of Feller patella scores and quadriceps muscle strength after 6 months were of significant difference compared with pre-operation and postoperative 6 months data (t = 5.65-10.65 and t = 2.18-2.73, P < 0.05) . Three knee reported continuing pains with quadriceps muscle strength less than 4 level. PFJ is an effective method for patello-femoral compartmental osteoarthritis with less trauma. The early term outcome of PFJ is encouraging. Quadriceps muscle strength should be enhanced.

Fresh Osteochondral Allografts for Patellofemoral Arthritis

Treatment of patellofemoral osteoarthritis in young patients is a challenge for orthopaedic surgeons. Concern about loosening and wear in active young people render arthroplasty more suitable for older patients. Osteochondral allografts may be a good alternative, but reports of experience with such grafts in patellofemoral joints are limited. We retrospectively reviewed our results with fresh osteochondral allografts. Our hypothesis was that these grafts provide relief from osteoarthritis, improve knee function, and delay prosthetic knee replacement. From 1986 to 1999, 14 fresh patellofemoral or patellar allografts were implanted in knees of 11 patients younger than 55 years and diagnosed with advanced secondary osteoarthritis. At last followup (average, 10 years; range, 2.5-17.5 years), eight grafts were in place, four for more than 10 years and two for more than 5 years. Of the nonsurviving allografts, three survived more than 10 years. Radiographs of the knees with intact allografts showed mild or no degenerative changes. Average Knee Society scores improved (preoperative to last followup), with knee scores improving from 46 points (range, 38-60 points) to 82 points (range, 35-100 points) and functional scores from 30 points (range, 10-60 points) to 75 points (range, 20-100 points). Fresh osteochondral allografts can provide relief from the arthritic condition, improve knee function, and delay prosthetic knee replacement. Therapeutic study, Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

The Treatment of Patellofemoral Osteoarthritis with Partial Lateral Facetectomy

We investigated the impact of the partial lateral facetectomy of the patella on middle-aged to elderly patients with isolated lateral patellofemoral osteoarthritis. Between 1991 and 2000, we performed partial lateral facetectomy on 11 knees in 11 patients with an average age of 62 years (range, 53-72 years). The mean followup was 8 years (range, 3-14). The average Knee Society Score improved from a preoperative score of 150 to a score of 176 at latest followup. Followup radiographs showed slow progression of osteoarthritis in the patellofemoral and tibiofemoral compartments, but radiographic appearance did not always correlate with clinical symptoms. The success of this procedure depends largely on relief of pain. Partial lateral facetectomy is relatively simple and effective surgical treatment for middle-aged to elderly active patients with isolated lateral patellofemoral osteoarthritis who want to maintain activity level. Therapeutic study, Level IV (case series--no, or historical control group). See the Guidelines for Authors for a complete description of levels of evidence.