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Patellar stress fracture
The Journal of Arthroplasty Vol. 14 No. 3 1999
Case Report Patellar Stress Fracture A Complication of Knee Joint Arthroplasty Without Patellar Resurfacing M . R. R e e d , F R C S , M . J. F a r h a n ,
FRCS, and
C. C h a u d h u r i ,
MS
Abstract: A case of patellar stress fracture after total knee arthroplasty in a man with
gout and previous osteonecrosis of the tali is reported. The combination of fat pad excision and lateral release causing disruption to the patellar blood supply during primary total knee arthroplasty resulted in the development of a patellar fracture. Avascular necrosis, caused by gout, may form part of the pathogenesis. Key words: patellar fracture, avascular necrosis, total knee arthroplasty.
p r e s e n t a t i o n for ankle pain, he was reviewed. He n o w complained m o r e of pain in his knees, and radiographs s h o w e d advanced degenerative changes associated with crystal deposition, the right k n e e worse t h a n the left. This pain affected his sleep a n d restricted his walking distance to 20 yards. His uric acid level was raised at 444 pmol/L. After 6 m o n t h s , he h a d a c e m e n t e d right total condylar prosthesis inserted using an anterior midline skin incision a n d a medial parapatellar a p p r o a c h to the joint. The fat pad was excised, patella osteophytes w e r e t r i m m e d , a n d it was necessary to p e r f o r m a lateral release. He m a d e an u n e v e n t f u l postoperative recovery and was discharged h o m e at 11 days with 95 ° of flexion. Radiographs at this stage w e r e satisfactory (Fig. 2). At 3 - m o n t h follow-up, he was f o u n d to h a v e an extensor lag of 10 °, which reduced to 5 ° at 6 m o n t h s . A radiograph revealed m a r k e d sclerosis of the patella highly suggestive of AVN w i t h a widely displaced transverse fracture (Fig. 3). On direct questioning, there was no history of a n y type of t r a u m a , and he denied a snapping sensation or sudden pain. Currently the patient is satisfied w i t h the result a n d denies a n y disability f r o m this knee. He has declined a n y further t r e a t m e n t for the right k n e e a n d is n o w awaiting left total k n e e arthroplasty.
Extensor m e c h a n i s m complications occur in 3% to 2 1 % [1] of cases after total k n e e arthroplasty. Lateral release a n d excision of the fat p a d disturb the blood supply to the patella e v e n w i t h o u t resurfacing, b u t stress fracture w i t h o u t resurfacing in total k n e e arthroplasty in osteoarthrosis r e m a i n s unreported. There h a v e b e e n m a n y case reports of avascular necrosis (AVN) of b o n e attributed to gout [2-5]. This case report describes a patient w i t h gout w h o was k n o w n to h a v e talar osteonecrosis t h e n developed a patellar stress fracture after total k n e e arthroplasty for (secondary) osteoarthrosis.
Case Report A 67-year-old m a n h a d AVN of b o t h tali attributable to gout (Fig. 1). He h a d no history of a n y other conditions predisposing to AVN, including steroid m e d i c a t i o n or alcohol abuse. Six m o n t h s after initial From the Department of Orthopaedics, Bassetlaw Hospital Nottinghamshire, England. Submitted December 12, 1997; accepted July 24, 1998. Reprint requests: M. R. Reed, FRCS, Department of Orthopaedics, Bassetlaw Hospital, Worksop, Nottinghamshire, $81 0BD, England. Copyright © 1999 by Churchill Livingstone ® 0883-5403/99/1403-0019510.00/0
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384
The Journal of Arthroplasty Vol. 14 No. 3 April 1999
Fig. 1. Ankle radiographs showing right (A) and left (B) talar avascular necrosis.
Discussion Scapinelli [6] and Bjorkstrom and Goldie [7] both described small geniculate arteries supplying an anastomotic ring, which lies in the connective tissue a r o u n d the patella. Medial parapatellar incision
interrupts the medial geniculate circulation. Lateral release disturbs the circulation fed by the anterior tibial recurrent and the superior and inferior lateral genicular arteries (Fig. 4). The fat pad, which was excised, contains transverse infrapatellar arteries that b r a n c h off to the inferior pole of the patella [8].
Fig. 2. Satisfactory postoperative radiograph,
Fig. 3. Radiograph at 6 months postoperatively showing patellar avascular necrosis and fracture.
Patellar Stress Fracture
•
Reed et al.
385
unable to find any other cases of atraumatic fracture after primary tibiofemoral joint arthroplasty for osteoarthrosis. Our patient probably preserved his extensor expansion, and the presence of the patella, albeit fractured, still maintained the quadriceps t e n d o n at a maximal distance from the center of rotation of the joint [12]. The c o m b i n a t i o n of medial arthrotomy, fat pad excision, and lateral release predisposed to pathological patellar fracture. The association b e t w e e n gout and AVN is well established [2-5]. AVN caused by gout m a y have contributed to the pathogenesis of this stress fracture. Patients with gout undergoing total knee arthroplasty should be w a r n e d of this possible complication.
References
Fig. 4. Patellar blood supply and the disruption caused by medial arthrotomy and lateral release. SG, supreme genicular artery; MSG, medial superior genicular artery; MIG, medial inferior genicular artery; LSG, lateral superior genicular artery; APE ascending parapatellar artery; OPP, oblique prepatellar artery; LIG, lateral inferior genicular artery; TIE transverse infrapatellar artery; ATR, anterior tibial recurrent artery.
Scuderi et a]. [8], using bone scans, s h o w e d a 56.4% incidence of patella vascular compromise (cold patellae) in total knee arthroplasty after patella resurfacing a n d lateral release. As in our case, no attempt was m a d e to preserve the lateral geniculate vessels. Bjorkstrom and Goldie [7] also described small vessels passing t h r o u g h the quadriceps t e n d o n to the patella but stated that in specimens from patients aged m o r e t h a n 60 years, the terminal endings did not penetrate into the subchondral bone. This m a y explain w h y a similar medial and lateral approach in y o u n g adults for open ligamentous repair p r o d u c e d cold patellae in only 14% of patients [8]. Patellar fracture after resurfacing has an incidence of 0.33% to 21.4% [9,10]. Four fractures have been reported w i t h o u t resurfacing [9,11] for r h e u m a t o i d arthritis but n o n e for osteoarthrosis. At least 3 patients had received steroids and had the posterior patellar surface resected. The authors were
1. Stulberg SD: Revision total knee arthroplasty: extensor mechanism complications after total knee arthroplasty. Orthopedics 18:919, 1995 2. McCollunr DE, Clippinger FW, O'Neil MT, Mathews RR: Aseptic necrosis of the femoral head: associated diseases and evaluation of treatment. J Bone Joint Surg Am 49:1019, 1967 3. Jacobs B: Epidemiology of traumatic and non traumatic osteonecrosis. Clin Orthop 130:51, 1978 4. Miskew DBW, Goldflies ML: Atraumatic avascular necrosis of the talus associated with hyperuricaemia. Clin Orthop 148:156, 1980 5. Hunder GG, Worthington JW, Bickel WH: Avascular necrosis of the femoral head in a patient with gout. JAMA 203:101, 1968 6. Scapinelli R: Blood supply of the human patella: its relation to ischaemic necrosis after fracture. J Bone Joint Surg Br 49:563, 1967 7. Bjorkstrom S, Goldie IF: A study of the arterial supply of the patella in the normal state, in chondromalacia patellae and in osteoarthrosis. Acta Orthop Scand 51:63, 1980 8. Scuderi G, Scharf S, Meltzer LE Scott WN: The relationship of lateral releases to patella viability in total knee arthroplasty. J Arthroplasty 2:209, 1987 9. Grace JN, Sire FH: Fracture of the patella after total knee arthroplasty. Clin Orthop 230:168, 1988 10. Cameron HU, Fedorkow DM: The patella in total knee arthroplasty. Clin Orthop 165:197, 1982 11. Freeman MAR, Hammer A: Patellar fracture after replacement of the tibio-femoral joint with the ICLH prosthesis. Arch Orthop Trauma Surg 92:63, 1978 12. Smillie IS: The function of the patella, p. 33. In: Diseases of the knee joint. 2nd ed. Churchill Livingstone, Edinburgh, 1980
Case Report Patellar Stress Fracture A Complication of Knee Joint Arthroplasty Without Patellar Resurfacing M . R. R e e d , F R C S , M . J. F a r h a n ,
FRCS, and
C. C h a u d h u r i ,
MS
Abstract: A case of patellar stress fracture after total knee arthroplasty in a man with
gout and previous osteonecrosis of the tali is reported. The combination of fat pad excision and lateral release causing disruption to the patellar blood supply during primary total knee arthroplasty resulted in the development of a patellar fracture. Avascular necrosis, caused by gout, may form part of the pathogenesis. Key words: patellar fracture, avascular necrosis, total knee arthroplasty.
p r e s e n t a t i o n for ankle pain, he was reviewed. He n o w complained m o r e of pain in his knees, and radiographs s h o w e d advanced degenerative changes associated with crystal deposition, the right k n e e worse t h a n the left. This pain affected his sleep a n d restricted his walking distance to 20 yards. His uric acid level was raised at 444 pmol/L. After 6 m o n t h s , he h a d a c e m e n t e d right total condylar prosthesis inserted using an anterior midline skin incision a n d a medial parapatellar a p p r o a c h to the joint. The fat pad was excised, patella osteophytes w e r e t r i m m e d , a n d it was necessary to p e r f o r m a lateral release. He m a d e an u n e v e n t f u l postoperative recovery and was discharged h o m e at 11 days with 95 ° of flexion. Radiographs at this stage w e r e satisfactory (Fig. 2). At 3 - m o n t h follow-up, he was f o u n d to h a v e an extensor lag of 10 °, which reduced to 5 ° at 6 m o n t h s . A radiograph revealed m a r k e d sclerosis of the patella highly suggestive of AVN w i t h a widely displaced transverse fracture (Fig. 3). On direct questioning, there was no history of a n y type of t r a u m a , and he denied a snapping sensation or sudden pain. Currently the patient is satisfied w i t h the result a n d denies a n y disability f r o m this knee. He has declined a n y further t r e a t m e n t for the right k n e e a n d is n o w awaiting left total k n e e arthroplasty.
Extensor m e c h a n i s m complications occur in 3% to 2 1 % [1] of cases after total k n e e arthroplasty. Lateral release a n d excision of the fat p a d disturb the blood supply to the patella e v e n w i t h o u t resurfacing, b u t stress fracture w i t h o u t resurfacing in total k n e e arthroplasty in osteoarthrosis r e m a i n s unreported. There h a v e b e e n m a n y case reports of avascular necrosis (AVN) of b o n e attributed to gout [2-5]. This case report describes a patient w i t h gout w h o was k n o w n to h a v e talar osteonecrosis t h e n developed a patellar stress fracture after total k n e e arthroplasty for (secondary) osteoarthrosis.
Case Report A 67-year-old m a n h a d AVN of b o t h tali attributable to gout (Fig. 1). He h a d no history of a n y other conditions predisposing to AVN, including steroid m e d i c a t i o n or alcohol abuse. Six m o n t h s after initial From the Department of Orthopaedics, Bassetlaw Hospital Nottinghamshire, England. Submitted December 12, 1997; accepted July 24, 1998. Reprint requests: M. R. Reed, FRCS, Department of Orthopaedics, Bassetlaw Hospital, Worksop, Nottinghamshire, $81 0BD, England. Copyright © 1999 by Churchill Livingstone ® 0883-5403/99/1403-0019510.00/0
383
384
The Journal of Arthroplasty Vol. 14 No. 3 April 1999
Fig. 1. Ankle radiographs showing right (A) and left (B) talar avascular necrosis.
Discussion Scapinelli [6] and Bjorkstrom and Goldie [7] both described small geniculate arteries supplying an anastomotic ring, which lies in the connective tissue a r o u n d the patella. Medial parapatellar incision
interrupts the medial geniculate circulation. Lateral release disturbs the circulation fed by the anterior tibial recurrent and the superior and inferior lateral genicular arteries (Fig. 4). The fat pad, which was excised, contains transverse infrapatellar arteries that b r a n c h off to the inferior pole of the patella [8].
Fig. 2. Satisfactory postoperative radiograph,
Fig. 3. Radiograph at 6 months postoperatively showing patellar avascular necrosis and fracture.
Patellar Stress Fracture
•
Reed et al.
385
unable to find any other cases of atraumatic fracture after primary tibiofemoral joint arthroplasty for osteoarthrosis. Our patient probably preserved his extensor expansion, and the presence of the patella, albeit fractured, still maintained the quadriceps t e n d o n at a maximal distance from the center of rotation of the joint [12]. The c o m b i n a t i o n of medial arthrotomy, fat pad excision, and lateral release predisposed to pathological patellar fracture. The association b e t w e e n gout and AVN is well established [2-5]. AVN caused by gout m a y have contributed to the pathogenesis of this stress fracture. Patients with gout undergoing total knee arthroplasty should be w a r n e d of this possible complication.
References
Fig. 4. Patellar blood supply and the disruption caused by medial arthrotomy and lateral release. SG, supreme genicular artery; MSG, medial superior genicular artery; MIG, medial inferior genicular artery; LSG, lateral superior genicular artery; APE ascending parapatellar artery; OPP, oblique prepatellar artery; LIG, lateral inferior genicular artery; TIE transverse infrapatellar artery; ATR, anterior tibial recurrent artery.
Scuderi et a]. [8], using bone scans, s h o w e d a 56.4% incidence of patella vascular compromise (cold patellae) in total knee arthroplasty after patella resurfacing a n d lateral release. As in our case, no attempt was m a d e to preserve the lateral geniculate vessels. Bjorkstrom and Goldie [7] also described small vessels passing t h r o u g h the quadriceps t e n d o n to the patella but stated that in specimens from patients aged m o r e t h a n 60 years, the terminal endings did not penetrate into the subchondral bone. This m a y explain w h y a similar medial and lateral approach in y o u n g adults for open ligamentous repair p r o d u c e d cold patellae in only 14% of patients [8]. Patellar fracture after resurfacing has an incidence of 0.33% to 21.4% [9,10]. Four fractures have been reported w i t h o u t resurfacing [9,11] for r h e u m a t o i d arthritis but n o n e for osteoarthrosis. At least 3 patients had received steroids and had the posterior patellar surface resected. The authors were
1. Stulberg SD: Revision total knee arthroplasty: extensor mechanism complications after total knee arthroplasty. Orthopedics 18:919, 1995 2. McCollunr DE, Clippinger FW, O'Neil MT, Mathews RR: Aseptic necrosis of the femoral head: associated diseases and evaluation of treatment. J Bone Joint Surg Am 49:1019, 1967 3. Jacobs B: Epidemiology of traumatic and non traumatic osteonecrosis. Clin Orthop 130:51, 1978 4. Miskew DBW, Goldflies ML: Atraumatic avascular necrosis of the talus associated with hyperuricaemia. Clin Orthop 148:156, 1980 5. Hunder GG, Worthington JW, Bickel WH: Avascular necrosis of the femoral head in a patient with gout. JAMA 203:101, 1968 6. Scapinelli R: Blood supply of the human patella: its relation to ischaemic necrosis after fracture. J Bone Joint Surg Br 49:563, 1967 7. Bjorkstrom S, Goldie IF: A study of the arterial supply of the patella in the normal state, in chondromalacia patellae and in osteoarthrosis. Acta Orthop Scand 51:63, 1980 8. Scuderi G, Scharf S, Meltzer LE Scott WN: The relationship of lateral releases to patella viability in total knee arthroplasty. J Arthroplasty 2:209, 1987 9. Grace JN, Sire FH: Fracture of the patella after total knee arthroplasty. Clin Orthop 230:168, 1988 10. Cameron HU, Fedorkow DM: The patella in total knee arthroplasty. Clin Orthop 165:197, 1982 11. Freeman MAR, Hammer A: Patellar fracture after replacement of the tibio-femoral joint with the ICLH prosthesis. Arch Orthop Trauma Surg 92:63, 1978 12. Smillie IS: The function of the patella, p. 33. In: Diseases of the knee joint. 2nd ed. Churchill Livingstone, Edinburgh, 1980