Unique patellofemoral alignment in a patient with a symptomatic bipartite patella

The Effect of Patellofemoral Maltracking and Patella Type on Symptomatic Bipartite Patella

Purpose The aim of this study is to investigate the relationship of trochlear dysplasia (TD) and patella type with bipartite patella (BP). Materials and methods A total of 5,081 knee MRIs taken in our institution were reviewed retrospectively. Patients with a history of knee surgery, previous or recent trauma, and rheumatologic involvement were excluded from the study. The MRIs of 49 patients with bipartite/multipartite patella were detected. Three patients were excluded: two patients had a tripartite variant, and one had multiple osseous dysplastic findings. Overall, 46 patients with BP were included in the study. BPs were classified as type I, II, and III. Patients were divided into symptomatic and asymptomatic groups according to the presence of edema within the bipartite fragment and adjacent patella. Patients were examined in terms of patella type, trochlear dysplasia, tuberosity-trochlear groove (TT-TG) difference, sulcus angle, and sulcus depth. Results There were 46 patients with BP (28 males and 18 females) (mean age: 33±9.5 years, range: 18-54). Thirty-eight bipartite fragments (82.6%) were type III and eight (17.4%) were type II. There was no type I BP. Seventeen (36.9%) were symptomatic, and 29 (63.1%) were asymptomatic. Seven of the type II (87.5%) and 10 of the type III (26.3%) bipartite fragments were symptomatic. The frequency and degree of trochlear dysplasia (p=0.007 and p=0.041, respectively) were found to be higher in symptomatic patients. The trochlear sulcus angle was higher (p=0.007) and the trochlear depth was lower (p=0.006) in the symptomatic group. No statistically significant difference was found (p=0.247) in terms of TT-TG difference. Type III and type IV patella were more common in the symptomatic group. Conclusion The current study shows that patellofemoral instability and patella type are associated with symptomatic BP. Patients with trochlear dysplasia, type II BP, and disproportionate patellar facet may have a significantly increased risk of symptomatic BP.

Outcomes of surgical treatment of symptomatic bipartite patella in teenage athletes

Bipartite patella affects about 2% of people. Most cases are asymptomatic; however, some develop anterior knee pain during sports. When conservative treatment fails, surgery can be considered. This study reports the outcomes of fragment excision with or without lateral release in teenage athletes with symptomatic bipartite patella. The study was approved by the College of Medicine Institutional Review Board. A retrospective review was performed. Patients were excluded if age >18 or had prior knee surgery. Data collected included age, gender, BMI, sports played, Saupe classification, conservative and surgical treatment, advanced imaging used, duration of follow-up, Lysholm Score and postoperative complications. Five teenage patients were studied. The average age was 15.6 years and BMI was 23. Sports played included basketball, football, track-and-field and soccer. All patients complained of anterior knee pain exacerbated by sports. All patients failed >6 months of conservative treatment. Saupe classification included four type III (superolateral) and one type II (lateral). Two patients had an MRI. Surgical treatment included two open excisions and three arthroscopic-assisted open excisions with lateral releases. The average Lysholm Score was 97. Postoperatively, all patients returned to presurgery sporting activity at an average of 9.8 weeks (range, 6-13 weeks). A 16-year-old male treated by open excision developed a postoperative wound infection. He was successfully treated with irrigation & debridement and antibiotics and returned to sports at 6 weeks. Symptomatic bipartite patella is an uncommon cause of anterior knee pain in adolescent athletes. When pain persists despite conservative care, fragment excision with or without lateral release resulted in excellent pain relief and return to full sporting activity in all cases.

Arthroscopic Management for Bipartite Patella: A Systematic Review

Background:

Bipartite patella is a rare congenital condition that becomes painful following direct trauma or an overuse injury. If it remains painful despite nonoperative treatment, surgery may be warranted. The current gold standard is open fragment excision or lateral release; however, arthroscopic management is also possible.

Purpose:

To investigate the safety and efficacy of arthroscopic treatment of painful bipartite patella.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

Using Medline and Embase, we systematically reviewed the literature as of March 8, 2020, using the subject headings “bipartite patella” and “arthroscopy” and related key terms. All levels of evidence involving human studies in English were included. Articles were excluded if only the abstract was published or the study was related to nonsurgical treatment or nonrelated diagnoses. Data related to journal/article information, demographic/clinical data, arthroscopic technique, length of follow-up, treatment outcomes, and complications were extracted.

Results:

Eleven articles with 43 patients were included in the review. Most patients (n = 34; 79%) underwent arthroscopic lateral release, while 16% (n = 7) had arthroscopic excision of the accessory fragment and 5% (n = 2) had arthroscopic excision and release. All patients except for one, who experienced postoperative trauma, were pain-free after arthroscopic treatment and were able to return to sports after a mean 2.6 months.

Conclusion:

This review demonstrated that arthroscopic management of painful bipartite patella is a safe and effective alternative to open surgical excision or release. However, all articles were case studies or small case series, owing to the rarity of the condition. In the future, higher-level studies comparing arthroscopic techniques and postoperative rehabilitation programs should be performed.

Magnetic resonance imaging for diagnosis of bipartite patella: usefulness and relationship with symptoms

Purpose

Bipartite patella is a rare developmental variation of the knee cap. We aimed to identify the magnetic resonance imaging (MRI) features of bipartite patella and evaluate the association with clinical symptoms.

Material and methods

MRI exams of 61 patients with bipartite variant were evaluated for types of bipartite patella, oedema around the synchondrosis, bipartite fragment height (FH), distance between the fragment and the patella (FPD), and signal characteristics within the synchondrosis. The study was designed with two observers in order to achieve intra- and interobserver compliance. Any other major knee pathologies that can cause pain were also recorded.

Results

Of the 61 participants the average age was 40.1 ± 14.3 years, 44 were males, and 17 were females. Fifty-nine of the bipartite fragments were located at the superolateral quadrant of the patella. There was oedema at the bipartite area in 35 patients. Ten of these patients had no major MRI diagnosis other than oedema, and they were classified as the symptomatic group. The age of the patients in the symptomatic group was statistically lower than in the asymptomatic group (p < 0.05). There was no statistically significant difference between the groups in terms of male and female distributions, signal types across the synchondrosis, and FH or FPD measurements (p > 0.05). High concordance correlation coefficients were observed on measurements.

Conclusions

MRI of the knee is highly accurate in evaluation of bipartite patella. To our knowledge; a detailed MRI analysis, like in our study, has not previously been performed, and our report is unique in showing that the symptomatic occurrence of bipartite patella is statistically higher in young patients.

Clinical Outcome of Arthroscopic Lateral Retinacular Release for Symptomatic Bipartite Patella in Athletes

PURPOSE

To report the results of arthroscopic lateral retinacular release without excision of the accessory fragment for treatment of symptomatic bipartite patella with a minimum 2-year follow-up.

METHODS

We retrospectively reviewed all cases of symptomatic type III bipartite patella confirmed by radiographs, computed tomography, and magnetic resonance imaging and treated with arthroscopic lateral release from 2005 to 2015. Patients with history of knee fractures or surgery, concomitant meniscal or anterior cruciate ligament (ACL) procedures, and severe arthritic changes of the patellofemoral joint were excluded. Patients were assessed by Kujala score, visual analog scale (VAS), Tegner Activity Scale (TAS), and time to return to sporting activities.

RESULTS

Ten patients (11 knees) were clinically reassessed after 69.6 ± 33.3 (range: 25-132; 95% confidence interval [CI]: 47.29-91.99) months from surgery. There was a significant improvement in Kujala (P < .05) and VAS scores (P < .05), and no differences were found between pre- and postoperative TAS scores (P > .05). No complications occurred during the follow-up period. All patients returned to sport after 42.3 ± 11.3 (range: 30-60; 95% CI: 34.71-49.84) days after surgery.

CONCLUSIONS

The arthroscopic lateral retinacular release of a symptomatic type III bipartite patella without excision of the accessory fragment allowed early return to sporting activities, with excellent symptom relief. Patients had significantly improved mean Kujala and VAS scores without a decrease in the mean TAS scores.

LEVEL OF EVIDENCE

Level IV, case series.

Editorial Commentary: Got Evidence? What We Really Need Is an Algorithm for Treating Symptomatic Bipartite Patella

Bipartite patella is an uncommon but potentially troublesome problem for young athletes. Numerous uncontrolled retrospective studies have reported good results after various treatments. What is needed are studies that will guide workup and support treatment decisions based on the condition of the cartilage surfaces of the fragment, presence of pseudoarthrosis, and size and location of the fragment. To support decisions, we need prospective comparative studies, either randomized or, at least, prospective cohort studies that identify patients at the time of presentation, document key decision points, and follow patients to successful resolution of symptoms.