- September 2008 - Volume 31 · Issue 9:
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Richard E. Jones
Severe isolated patellofemoral arthrosis is a difficult problem for patients, and surgeons are confronted with many treatment options. Recent review articles by Grelsamer and Stein1 and Mihalko et al2 document the myriad surgical approaches. Older patients frequently have tricompartmental total knee arthroplasty (TKA) or patellofemoral arthroplasty, but these choices subject the patient to possible complications of permanent implants. Various osteotomies and realignment procedures have been described, but they have produced inconsistent results. Arthroscopic intervention is a less invasive, more conservative approach to severe isolated patellofemoral arthrosis. We tested the hypothesis that arthroscopic lateral patella facetectomy would provide significant relief for severe isolated patellofemoral arthrosis.
Materials and Methods
Over a 4-year period, 39 consecutive patients underwent arthroscopic lateral patella facetectomy. All patients reported primary anterior knee pain while climbing stairs and rising from a sitting to a standing position. Weight-bearing symptoms did not represent a predominant component of the patients complaints.
On physical examination, patients demonstrated patellofemoral crepitus and poor medial patella excursion. All patients reported no relief with conservative treatment such as nonsteroidal anti-inflammatory drugs, exercise, or steroid injections. All exhibited radiographic changes consistent with severe patellofemoral arthrosis on the Merchant view of the knee with loss of joint interval, increased bone density at the patellofemoral margins, lateral patella tilt, and an overriding lateral patella facet osteophyte (Figure 1). Patients exhibited minimal radiographic evidence of arthrosis in the medial and lateral compartments.
Patients underwent arthroscopic lateral patella facetectomy under general anesthesia. Injection with 0.25% bupivicaine with epinephrine was performed into the knee portals and along the lateral border of the patella in the region of the facetectomy. A routine arthroscopic procedure was performed for the medial and lateral compartments with debridement of any meniscal flap tears. The arthroscope was then introduced from the medial, inferior portal under the patella to visualize the patellofemoral compartment laterally.
Superior or inferior lateral portals were used for introduction of the arthroscopic instruments, which included a 5.5-mm acromioplasty burr. Under direct visualization, the lateral osteophyte was resected with the burr starting inferior lateral and proceeding superiorly. The resection was performed over to the high point of the lateral trochlear ridge on the femur. Prominent lateral trochlear osteophytes were also resected (Figures 2-5).
After facetectomy the patella was evaluated for medial patella excursion to confirm the decompression had been adequately performed. No formal lateral retinacular release was necessary because the removal of the lateral patella facet produces an interosseous lateral release. Finally, the knees were again injected with 0.25% bupivicaine with epinephrine along the area of the patella facet resection and intra-articular.
| |Figure 1:
A bulky compressive dressing with a lateral stint (a 4-inch rolled bandage) is necessary to provide compression over the area of resection. The lateral stint and compressive dressing remain on the patient for 2 to 3 weeks to prevent any herniation. Postoperatively, patients were taught patella excursion exercises and begun on a stationary bicycle with full weight bearing as tolerated.
Patients were evaluated with visual analog pain scales preoperatively at 3 weeks, 3 months, and 1 year for resting, stair climbing, and chair rising pain. Postoperative Merchant views of the knee were taken to document the completeness of the facetectomy.
All patients demonstrated increased patella excursion after the operative intervention. Postoperative radiographs confirmed removal of the overriding lateral facet and decompression of the patellofemoral compartment (Figure 6). A paired t test was used to analyze the data collected. Significant pain relief (P<.001) was seen in all 3 categories: pain at rest, pain while rising from a seated position, and pain while stair climbing. Maximum benefit of the procedure was noted at 6 months postoperatively and remained consistent at 1 year postoperatively. To our knowledge only 2 patients have undergone other operative procedures, total knee arthroplasty (TKA) in both cases.
The majority of patients with mild patellofemoral arthritis can be treated with conservative means. Activity modification, nonsteroidal anti-inflammatory drugs, good nutritional choices to lose weight and diminish stress, physical therapy, and bracing are some of those options. However, when the disease progresses and becomes symptomatic severe isolated patellofemoral arthrosis, intervention is necessary.
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|Figure 2: Arthroscopic view of concave overriding lateral facet. Figure 3: Arthroscopic view of 5.5-mm burr resecting lateral facet. Figure 4: Arthroscopic view of a burr continuing lateral facet resection. Note lateral retinaculum exposed in inferior picture. |
Laskin and Van Steijn3 reported 81% good to excellent results in 43 of 53 patients undergoing TKA. Parvizi et al4 reported that 21 of 31 TKAs performed for severe isolated patellofemoral arthrosis required lateral retinacular release and 3 more required more extensive realignment. This study documents that severe isolated patellofemoral arthrosis can complicate routine TKA. Total knee arthroplasty should be reserved for elderly, inactive patients as it may sacrifice healthy tissue with surgical dissection for a patient with an arthritic process involving only one compartment.
| |Figure 5:
Arthroscopic portal positions.
Patellofemoral replacement surgery has not achieved wide acceptance because of inconsistent results. Early reports of newer implant systems for patellofemoral compartment replacement may provide a stronger basis for continuing this procedure. However, DeCloedt et al5 found only 43% of 21 patients had a good result. The main cause of failure was degeneration of the femoral tibial compartments.
Numerous other realignment procedures have been recommended. One additional article has been reported on patella facetectomy for severe isolated patellofemoral arthritis. Yercan et al6 had only 11 patients and they all improved their Knee Society functional scores. No improvements were statistically significant in this small series.
| |Figure 6:
Our results confirm the hypothesis that arthroscopic lateral patella facetectomy provided statistically significant clinical improvement in patients with severe isolated patellofemoral arthritis. Anterior knee pain continued to improve over the 1-year postoperative period. The procedure may provide a more conservative approach in the patient population with severe isolated patellofemoral arthritis and may dispense with the need for TKA.
- Grelsamer RP, Stein DA. Current concepts review, patella femoral arthritis. J Bone Joint Surg Am. 2006; 88(8):1849-1860.
- Mihalko WM, Yaw D, Spang JT, et at. Controversies and techniques in the surgical management of patella femoral arthritis. J Bone Joint Surg Am. 2007; 89(12):2788-2802.
- Laskin SF, Van Steijn M. Total knee replacement for patients with patella femoral arthritis. Clin Orthop Relat Res. 1999; (367):89-95.
- Parvizi J, Stewart MJ, Pagnano MW, Hansen AD. Total knee arthroplasty in patients with isolated patella femoral arthritis. Clin Orthop Relat Res. 2001; (392):147-152.
- DeCloedt P, LeGaye J, Lokietek W. Femoral-patella prosthesis: A retrospective study of 45 consecutive cases with a follow-up of 3-12 years. Acta Orthop Belg. 1999; 65:160-175.
- Yercan HS, Alt ST, Neyret P. The treatment of patella femoral osteoarthritis with lateral patella facetectomy. Clin Orthop Relat Res. 2005; (436):14-19.
Dr Jones is from the Department of Orthopedic Surgery, UT Southwestern Medical School, Dallas, Texas; and Dr Rumack is from the Department of Orthopedic Surgery, Orthopedic Medical Center, Reseda, California.
Drs Jones and Rumack have no relevant financial relationships to disclose.
Correspondence should be addressed to: Richard E. Jones, MD, Orthopedic Specialists, 5920 Forest Park Rd, #600, Dallas, TX 75235.