We all strive to satisfy our patients and precise surgical indications are key to achieving this goal. For medial osteoarthritis, treatment options include HTO and partial and total knee arthroplasty. Those patients who also have patellofemoral (PF) pain and arthritis add additional complexity when making the final decision. Regardless of the treatment, however, some patients will experience persistent anterior knee pain, even in patients who undergo TKA and receive patella resurfacing. Thus, any preoperative screening that would identify patients at-risk for postoperative anterior knee pain is valuable.
Jeong and colleagues published a retrospective study of excessive lateral compression syndrome (ELCS) in medial OA patients. They utilize a potentially useful screening tool to optimize indications and thus postoperative outcomes. Scott Dye previously demonstrated that SPECT CT/bone scan can detect bone metabolism changes earlier than MRI (noting that SPECT is much less utilized and available than MRI in the United States). In the current study utilizing SPECT to evaluate patients with medial OA for ELCS, Jeong and colleagues identified that more than half of patients had increased lateral patellofemoral uptake, and 16% had evidence of established ELCS. However, it must be kept in mind that this was an imaging study without clinical correlation, yet it leads the way for potential future studies that could correlate outcomes of HTO with the presence of ELCS.
The first step in solving any problem is identifying there is a problem. In orthopedics, and life, most problems are multifactorial. While Jeong and colleagues did not identify specific risk factors associated with ELCS, they did suggest treatments to address it during HTO through lateral release or tibial tubercle osteotomy. In regard to lateral release, in vitro cadaver studies have not demonstrated “unloading” of the patellofemoral compartment. On the other hand, medial tibial tuberosity transfer may decrease lateral patellofemoral loads as shown by Fulkerson and others.
As a cautionary note, the majority of varus knees with medial OA have been shown to have medial rather than lateral patellofemoral chondrosis. This medial patellofemoral OA is “unloaded” with the valgus realignment of HTO and unicondylar knee arthroplasty by increasing the lateral patellofemoral force vector through lateralization of the tubercle. In a large series of Oxford UKAs, Beard and colleagues reported that patellofemoral OA did not influence the outcomes of medial UKA. In summary, Jeong and colleagues point to one additional factor potentially influencing post-HTO patellofemoral pain that desires clinical scrutiny and further study.
Beard DJ, et al. J Bone Joint Surg. 2007;doi:10.1302/0301-620X.89B12.19259.
Beck PR, et al. Am J Sports Med. 2005;doi:10.1177/0363546505278300.
Dye SF, et al. Orthop Clin North Am. 1986;17:249-262.
Elahi S, et a. Arthritis Rheum. 2000;doi:10.1002/1529-0131(200008)43%3A8<1874%3A%3AID-ANR25>3.0.CO; 2-2.
Fulkerson JP, et al. Am J Sports Med. 1990;18:490-497.
Huberti HH, et al. J Orthop Res. 1988;6:499-508.
Lewallen DG, et al. J Orthop Res. 1990;8:856-862.
Ostermeier S, et al. Knee Surg Sports Traumatol Arthrosc. 2007;doiI:10.1007/s00167-006-0261-0.
Ramappa AJ, et al. Am J Sports Med. 2006;doi:10.1177/0363546505283460.
Jack Farr, MD
OrthoIndy Knee Preservation and Cartilage Restoration Center
Andreas Gomoll, MD
Hospital for Special Surgery
Disclosures: Farr and Gomoll report no relevant financial disclosures.