Surgical options for chronic patellar tendon rupture in total knee arthroplasty.
OBJECTIVE
The purpose of this study was to compare mid-term results of three different reconstructive techniques for chronic patellar tendon disruption after total knee arthroplasty (TKA). Several surgical techniques have been proposed, but to date it is still unclear which is the best solution. The hypothesis was that allografts provide better functional results than autografts in restoring a correct joint function.


METHODS
Twenty-one reconstructions were performed in twenty-one patients (three groups of seven patients) with chronic patellar tendon lesion following TKA. Group I underwent reconstruction with an Achilles tendon allograft with a calcaneal block, Group II with an autograft of the quadriceps tendon reinforced by the semitendinosus tendon and Group III with a full extensor mechanism allograft consisting of the tibial tubercle, patellar tendon, patella, and quadriceps tendon. Preoperatively and at each follow-up, the value of the extensor lag and the Knee Score (KS) were recorded.


RESULTS
The mean extensor lag decreased from 50° ± 19.4° to 3° ± 1.6°. The KSS improved from 44.7 ± 20.5 to 78.9 ± 13.6 points. The comparison between the groups showed statistically significant differences in the mean postoperative KS between Groups I (average score of 87.7 ± 14.3 points) and II (average score of 70 ± 4.1 points), but not between Groups I and III (average score of 78.9 ± 14.6 points) or between Groups II and III. Differences in the postoperative extensor lag were not significant between the three groups.


CONCLUSIONS
The present study may serve surgeons in choosing the best reconstructive strategy for a chronic patellar tendon lesion in TKA. According to the reported results, an Achilles tendon allograft should be considered the gold standard repair. The autograft technique is suitable when the host tissue is competent, particularly when dealing with younger patients or post-infection. A full extensor mechanism allograft may represent a reliable solution when the defect involves the patellar bone or the quadriceps tendon.


METHODS
IV.
IFCA, Istituto Fiorentino di Cura e Assistenza, Via del Pergolino 4, 50139, Florence, Italy. alfredo.lamberti@hotmail.it.
Alfredo
http://orcid.org/0000-0003-2359-182X
A
Lamberti
IFCA, Istituto Fiorentino di Cura e Assistenza, Via del Pergolino 4, 50139, Florence, Italy.
Giovanni
G
Balato
IFCA, Istituto Fiorentino di Cura e Assistenza, Via del Pergolino 4, 50139, Florence, Italy.
Pier Paolo
PP
Summa
Medanta Bone and Joint Institute, Medanta- The Medicity, Gurgaon, Haryana, India.
Ashok
A
Rajgopal
Medanta Bone and Joint Institute, Medanta- The Medicity, Gurgaon, Haryana, India.
Attique
A
Vasdev
IFCA, Istituto Fiorentino di Cura e Assistenza, Via del Pergolino 4, 50139, Florence, Italy.
Andrea
A
Baldini
D000125:Achilles Tendon / Q000637:transplantation; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D005500:Follow-Up Studies; D000070632:Hamstring Tendons / Q000637:transplantation; D006801:Humans; D007718:Knee Injuries / Q000209:etiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D017847:Patellar Ligament / Q000293:injuries* / Q000601:surgery; D011183:Postoperative Complications / Q000601:surgery*; D012189:Retrospective Studies; D012421:Rupture / Q000209:etiology / Q000601:surgery*; D013708:Tendon Injuries / Q000209:etiology / Q000601:surgery*; D014182:Transplantation, Autologous; D014184:Transplantation, Homologous; D016896:Treatment Outcome
Allograft; Autograft; Extensor mechanism; Patellar tendon; Reconstruction; Total knee arthroplasty