Extended proximal trochleoplasty for the correction of bidirectional patellar luxation in seven Pomeranian dogs

Abstract

Seven Pomeranians with bidirectional patellar luxation (BPL) were prospectively studied regarding aetiology and results of a new surgical technique. Radiographic evaluation of the ratio between patellar ligament length and patellar bone length revealed no differences between Pomeranians with bidirectional patellar luxation and healthy stifle joints. Functional rather than anatomic patella alta might be associated with bidirectional patellar luxation in Pomeranians. The surgical outcome of extended proximal trochleoplasty was good-to-excellent in 87·5% of the stifles and all dogs achieved functional recovery. There was only minimal radiographic progression of osteophyte formation at 48 weeks after surgery. To the authors' knowledge, this is the first report on bidirectional patellar luxation in small breed dogs and its successful surgical treatment.

Kite Shield‐Shaped Wedge Recession for Treatment of Medial Patellar Luxation in Seven Small‐Breed Dogs

“…This study shows that K‐wedge recession trochleoplasty significantly increased the coverage of the proximal trochlear by the patella, which was maintained at 12 months postoperative without lameness. Minimal progression of osteophyte presence was identified 12 months postoperative, as reported previously . The K‐wedge recession trochleoplasty offers an alternate to modified wedge recession with proximal excisional trochleoplasty in dogs with MPL.…”

“…The proximal end of the K‐wedge is in the cortical bone of the distal femur, which is 2–3 mm proximal from the patella position with the stifle extended. Wangdee et al reported that the periosteum should be continuous with the wedge to allow for blood supply. Wangdee et al also recommended that the exposed cancellous and cortical bone of the distal femur should be covered to reduce enthesophyte formation at the proximal patella and osteophyte formation in the extended trochlea.…”

“…Wangdee et al reported that the periosteum should be continuous with the wedge to allow for blood supply. Wangdee et al also recommended that the exposed cancellous and cortical bone of the distal femur should be covered to reduce enthesophyte formation at the proximal patella and osteophyte formation in the extended trochlea. In the present study, osteophytes were present at the proximal trochlear postoperative, which was expected as the K‐wedge was created without a proximal periosteal attachment.…”

“…Adequate recession of the proximal trochlea is necessary to stabilize the patella in the proximal trochlea . Wangdee et al reported an extended, wedge‐type, proximal trochleoplasty for the correction of patella luxation, which maintained periosteal attachment of the wedge. This technique can be challenging and, thus, a technique for patellar luxation in dogs that deepens the proximal trochlea but preserves the hyaline articular cartilage surface of the trochlea is required.…”

Proximo-distal patellar position in three small dog breeds with medial patellar luxation

“…A proximal position of the patella in the trochlear groove in stance may coincide with bidirectional patellar luxation in Pomeranians, even though the L:P ratio is normal (13). This might be because functional patella alta is a result of hyperextension of the stifle joint during locomotion rather than a long patellar ligament (16).…”