Treatment of Fabella syndrome with arthroscopic fabellectomy: a case series and literature review

Background The fabella is a sesamoid bone in the posterolateral capsule of the human knee joint. In quadrupedal mammals, the fabella is believed to have a role similar to the patella in redirecting extension forces of the knee joint from one point to another. In bipeds, the fabella is not touching the back of the bent knee, and therefore the role in redirecting forces declines. Posterolateral knee pain can be associated with the irritation between the fabella and lateral femoral condyle, a phenomenon also known as fabella syndrome. In cases that are unresponsive to conservative management, surgical fabellectomy can be a successful treatment option. Among the surgical approaches, open resection is most commonly seen. There are also literature reporting arthroscopic-assisted open resection, but seldom mentioned the all-arthroscopic fabellectomy. Case presentation We present 3 patients with a long history (> 12 month) of posterolateral knee pain under suspicion of different pain origins. The diagnosis of fabella impingement was eventually made by ruling out of other causes. All the patients underwent all-arthroscopic fabellectomy for diagnosis and treatment. Investigations of the resected fabella suggested chronic impingement with apparent osteophyte formation and cartilage wearing of the articular side. All patients have been continually followed up at our outpatient department and reported to be pain free after the procedure. Conclusions In the patients presenting posterolateral pain, fabella syndrome cannot be ignored due to its relative higher presence in Asian population. In our experience, the all-arthroscopic fabellectomy offers a smaller wound size, less post-operative pain, fewer days of hospitalization and quicker time to rehabilitation for the patients with chronic posterolateral knee pain caused by fabella syndrome.

Quantitative and Qualitative Assessment of Posterolateral Meniscal Anatomy: Defining the Popliteal Hiatus, Popliteomeniscal Fascicles, and the Lateral Meniscotibial Ligament

Background: Surgical treatment of lateral meniscal tears can be challenging due to the greater mobility of the lateral meniscus, thin capsule, and management of the popliteal hiatus. There has been a lack of quantitative assessments of the structural attachments to the posterior horn of the lateral meniscus (PHLM) to guide repairs. Purpose: To qualitatively and quantitatively describe the anatomy of the PHLM, popliteomeniscal fascicles, and the posterolateral capsule. Study Design: Descriptive laboratory study. Methods: Fourteen male, nonpaired, fresh-frozen cadaveric knees were used. The attachments of the posterolateral capsule, popliteomeniscal fascicles, and meniscofemoral ligaments to the lateral meniscus and the attachment of the meniscotibial ligament to the tibia were identified. A 3-dimensional coordinate measuring system was used to measure the relationships of these attachments to surgically relevant landmarks and their structural relationship with the lateral meniscus. Results: The posterolateral capsule attachment had a confluent attachment at the superior margin of the PHLM, quantitatively attaching to the proximal 11% of the total height of the PHLM. On average, the length of the posterolateral capsule attachment to the superior surface of the PHLM was 16.7 ± 2.7 mm. The average length of the meniscotibial attachment to the posteroinferior aspect of the meniscus was 12.8 ± 3.9 mm. There was a lack of ligamentous attachments to the lateral meniscus between the lateral aspect of the meniscotibial ligament and the anterior aspect of the anterosuperior popliteomeniscal fascicle, where only popliteomeniscal fascicle and capsular attachments to the posterior meniscus were present. Conclusion: This anatomic study provides quantitative guidelines for the complex attachments to the PHLM. Knowledge of the quantitative descriptions of these attachments may aid in an improved intraoperative diagnosis of PHLM tears that extend to the popliteal hiatus, and further studies related to the surgical repair of the intricate attachments to the PHLM are recommended. Clinical Relevance: The findings of this study provide the anatomic foundation for an improved understanding of the role of the meniscocapsular, meniscotibial, and popliteomeniscal fascicle attachments of the posterolateral meniscus. Understanding the differences between the lengths of the superior and inferior aspects of the popliteal hiatus will help to further refine characterization of tears extending into the popliteal hiatus and to avoid potential overconstraint of the more mobile lateral meniscus during a repair by anatomically reproducing its native structural attachments.

Sequential two stage release for genu valgum correction in total knee replacement

<p class="abstract"><strong>Background:</strong> <span lang="EN-IN">Valgus deformity presents a major challenge in total knee replacement, especially in moderate or severe cases. Many surgical techniques have been described to balancethe soft tissues in correction of a severe valgus deformityduring total knee replacement. The structures most commonlyreleased in a valgus knee include the posterolateralaspect of the capsule, iliotibial band (IT band), the lateral collateral ligament (LCL), the popliteustendon, and the lateral head of the gastrocnemius muscle.</span></p><p class="abstract"><strong>Methods:</strong> <span lang="EN-IN">thirty two patients undergoing unilateral total knee replacement were followed for the evaluation of study. There were 22 female (68%) and 10 males (32%) with an age of 62.7±6.9 years (range 50-75) with valgus deformity of 18.59˚±8.32˚ (range 10-40˚). Preoperative diagnosis was rheumatoid arthritis in 23 patients (72%) and osteoarthritis in 9 patients (28%). Posterior stabilizing cemented implants were used</span>.<strong></strong></p><p class="abstract"><strong>Results:</strong> <span lang="EN-IN">Based on total knee score we achieved 21 (63.64%) excellent, 10 (31.82%) good and 1 (4%) fair results. With the total functional score we had 16 (50%) excellent, 15 (45.45%) good and 1 (4%) fair results. In patients with only step1 release (17 patients) we achieved 84% (15 pts) excellent, 8% (1 pt) good, 8% (1 pt) fair with knee score; and 67% (11pts) excellent, 33% (6pts) good with functional score. In step 2 release group (15 pt) we achieved 10% (1 pt) excellent, 90% (14 pts) good with knee score; and 10% (1pt) excellent, 80% (13 pts) good and 10% (1 pt) fair with functional score. </span></p><p class="abstract"><strong>Conclusions:</strong> <span lang="EN-IN">Good to excellent results can be achieved with two step sequential lateral release of posterolateral capsule and IT band pie-crusting which has direct correlation with severity of valgus deformity. The safety, simplicity, and high success rate of the two step sequential lateral release of posterolateral capsule and pie-crusting of IT band justify its routine use to correct every valgus deformity in total knee replacement.</span></p>