Abstract
One hundred patients with the diagnosis of an acute patellar dislocation treated conservatively and 30 healthy control subjects were studied roentgenographically by lateral and tangential views. The aim of the study was to determine the distribution and incidence of predisposing factors in different study groups. Three study groups were formed as follows: 67 patients (group A) without late problems or operative treatment of redislocation: 33 patients (group B) who underwent a surgical realignment procedure for redislocations or late problems; and 30 healthy control subjects (group C). A statistically significant difference was observed between the patient groups (A, B) and control group (C) when the means, medians and distributions of patellar tendon length (LT), patellar length (LP), tendon to patellar length ratio (LT/LP), tendon to patellar articular surface ratio (LT/LAS), sulcus angle (SA), lateral patellar displacement (LPD), lateral patellofemoral angle (LPA) and morphological classification of the patella (1–5, Jägerhut) were compared. In group A, LPD was also significantly greater than in group B. This study demonstrates a considerably high rate of predisposing factors associated with patellar dislocation.
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Baumgartl F (1966) Anatomische und klinische Bedeutung des Femoro-patellargelenkes. Zentralbl Chir 91: 505–516
Brattström H (1964) Shape of the intercondylar groove normally and in recurrent dislocation of the patella. A clinical and X-ray anatomic investigation. Acta Orthop Scand [Suppl]: 1–30
Carson WG, James SL, Larson RL, et al (1984) Patellofemoral disorders: physical and radiographic evaluation. II. Physical examination. Clin Orthop 185: 165–177
Carson WG, James SL, Larson RL, et al (1984) Patellofemoral disorders: physical and radiographic evaluation. II. Radiographic examination. Clin Orthop 185: 178–186
Carter C, Sweetnam R (1958) Familial joint laxity and recurrent dislocation of the patella. J. Bone Joint Surg [Br] 40: 664–667
Cash JO, Hughston JC (1988) Treatment of acute patellar dislocation. Am J Sports Med 14: 117–120
Cofield RH, Bryan RS (1977) Acute dislocation of the patella. Results of conservative treatment. J. Trauma 17: 526–531
Cross MJ, Waldrop J (1976) The patella index as a guide to the understanding and diagnosis of patellofemoral instability. Clin Orthop 110: 174–177
Grelsamer RP, Meadows S (1992) The modified Insall-Salvati ratio for assessment of patellar height. Clin Orthop 282: 170–176
Grelsamer RP, Proctor CS, Bazos AN (1994) Evaluation of the patellar shape in the sagittal plane. A clinical analysis. Am J Sports Med 22: 61–66
Harilainen A, Myllynen P (1988) Operative treatment in acute patellar dislocation: radiological predisposing factors, diagnosis and results. Am J Knee Surg 1: 178–185
Helfet AJ (1982) Disorders of the knee. Lippincott, Philadelphia
Hauser EDW (1926) Total tendon transplant for slipping patella. Surg Gynecol Obstet 260: 521
Hughston JC (1968) Subluxation of the patella. J Bone Joint Surg [Am] 50: 1003–1026
Hughston JC, Walsh WM, Puddu G (1984) Patellar subluxation and dislocation. (Saunders monographs in clinical orthopeaedics, vol. 5) Saunders, Philadelphia, pp 84–114
Insall J, Goldberg V, Salvati E (1972) Recurrent dislocation and the high-riding patella. Clin Orthop 88: 67–69
Insall J, Salvati E (1971) Patella position in the normal knee joint. Radiology 101: 101–104
Jackson AM (1992) Recurrent dislocation of the patella. J Bone Joint Surg [Br] 74: 2–4
Jensen CM, Roosen JU (1985) Acute traumatic dislocations of the patella. J Trauma 25: 160–162
Krogius A (1904) Zur Operative Behandlung der habituellen Luxation der Kniescheibe. Zentralbl Chir 31: 254
Larsen E, Lauridsen F (1982) Conservative treatment of patellar dislocations. Influence of evident factors on the tendency to redislocation and the therapeutic result. Clin Orthop 171: 131–136
Laurin CA, Levasque HP, Dussault R, et al (1978) The abnormal lateral patellofemoral angle. A diagnostic roentgenographic sign of recurrent patellar subluxation. J Bone Joint Surg [Am] 60: 55–60
Laurin CA, Dussault R, Levesque HP (1979) The tangential X-ray investigation of the patellofemoral joint: X-ray technique. diagnostic criteria and their interpretation. Clin Orthop, 144: 16–26
Mäenpää H, Lehto MUK (1997) The dislocating patella. Long term results of conservative management in 100 patients. Am J Sports Med (in press)
Merchant AC, Mercer RL, Jacobsen RH, et al (1974) Roentgenographic analysis of patellofemoral congruence. J Bone Joint Surg [Am] 56: 1391–1396
Runow A (1983) The dislocating patella. Etiology and prognosis in relation to generalized joint laxity and anatomy of patellar articulation. Acta Orthop Scand [Suppl] 201: 5–46
Schlenzka D, Schwesinger G (1990) The height of the patella: an anatomical study. Eur J Radiol 11: 19–21
Wiberg G (1941) Roentgenographic and anatomic studies of the patellofemoral joint. Acta Orthop Scand 12: 319–410
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Mäenpää, H., Lehto, M.U.K. Patellar dislocation has predisposing factors. Knee Surg, Sports traumatol, Arthroscopy 4, 212–216 (1996). https://doi.org/10.1007/BF01567965
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DOI: https://doi.org/10.1007/BF01567965