An Unusual Source Of Wrist Pain
Kienbock's Disease in a Weight Lifter
Frank C. McCue III, MID
Omar D. Hussamy, MB, BChir, MID
Thomas E. Baumgarten, MID
Pediatrics Series
Edftor: Barry Goldberg, IVID
After weight lifting, a 15-yearold boy felt pain in his right wrist, had tenderness over the dorsum of the lunate, and had limited wrist motion. Radiographs revealed avascular necrosis of the lunate, or Kienbock's disease, and negative ulnar variance. The patient was successfully treated with an ulnar lengthening procedure and immobilization. This patient's symptoms are typical of Kienbock’s disease, which should be considered in the differential diagnosis of any active patient who has wrist pain and limited wrist motion. Treatment of this rare disorder can include immobilization for earlystage disease, or surgery, which is most likely to provide an optimal outcome.
Kienbock's disease-- avascular necrosis of the lunate-- was initially described in 1910 by Robert Kienbock, and Austrian radiologist. Untreated, the lunate will collapse, causing disruption of the wrist's articulation, pain, loss of motion, and eventually osteoarthritis. Much debate has surrounded the etiology and management of this condition, which primarily affects men between 18 and 40 years of age More than 95% of patients perform manual labor involving the upper extremities? The adolescent described in this case report developed Kienbocks disease after bench-pressing. To our knowledge, this rare disease has not been previously reported in a weight lifter, which underscores the importance of staying alert to its presence in active patients who report wrist pain.
Case Report
A 15-year-old right-handed boy experienced pain in his right wrist. The patient, a recreational weight lifter, reported the onset of symptoms after a bench-pressing session during which he lifted 150 1b. He had felt no "crack' or "pop." The pain gradually worsened and was present with any activity involving the right upper extremity He presented to our office 2 weeks later. He re-ported no previous wrist pain or injury to the wrist.
On physical examination, the wrist was ten-der over the dorsurn of the lunate. The patient had no synovitis. His right wrist lacked 15* of dorsiflexion and 20* of palmar flexion when compared with the left. Plain radiographs showed negative u1nar variance and sclerosis of the lunate, with no lunate collapse.
A diagnosis of stage 2 Kienbocks disease was made The patient underwent an ulnar-length-ening osteotomy with iliac crest bone graft and plate fixation. He was initially placed in a long arm cast for 2 weeks and then a short-arm cast.
Four weeks postoperatively, the patient fell, breaking the tubular plate. He was placed back in a long-arm cast, but 4 weeks later x-rays showed increased angulation and no evidence of healing at the osteotomy site. He underwent repeat open reduction and internal fixation us-ing a dynamic compression plate and iliac crest bone graft. He was kept in a long-arm cast for 2 more weeks and a short-arm cast for 4 addition-al weeks. Radiographs showed healing of the osteotomy site and incorporation of the bone graft. Immobilization was discontinued, and he began an active range-of-motion program. One month later, he graduated to an exercise program and progressive strength training.
Four months after the second operation he was pain free, lacking only 15 de of dorsiflexion. Radiographs revealed a normal-appearing lunate with no sclerosis and a healed osteotomy site. He was released to full activities, including weight weight lifting and remains asymptomatic with a nontender wrist The hardware remains in place which is typical. His slight loss of dorsiflexion does not place him at significant risk of reinjury.
Uncertain Etiology
The cause of Kienbocks disease is unknown. The disease sometimes begins with a simple fracture or multiple compression fractures caused by repeated stresses across the wrist. Traurna. may or may not precede symptoms. The loss of blood supply to the lunate has been attributed to many factors, including traumatic interference with circulation, ligament injury with degeneration and collapse, primary circula-tory or vascular problems, and solitary or chron-ic injuries resulting in vascular impairment In our patient, onset of symptoms followed a ses-sion of bench-pressing, although there was no single traumatic event.
Kienbocks disease is commonly associated with negative u1nar variance, in which the ulnar head lies more proximal than the radial head on posteroanterior x-ray. (Neutral ulnar variance means the distal surfaces of the radius and ulna are level.) Gelberman et al showed that patients who have unilateral Kienbock's disease have a greater average negative ulnar variance than patients who have nominal wrists. This association, however, is not constant. Negative ulnar variance is a predisposing factor in Kienbock`s disease but is not a primary cause of the disease process.
Key Physical and Radiographic Findings History and physical. Most patients who have kienbock’s disease report that a wrist injury caused the symptoms, but the trauma is usually not severe. other patients have wrist pain with no previous injury' Usually, pain progresses in severity. Physical exam typically reveals a mod- erately swollen wrist vvith limitation of dorsiflex ion and palmar flexion as well as reduction in grip strength of at least 50%. (Grip strength is usually lost later in the disease process.) Pronation and supination are not affected. Carpal tunnel syndrome is found in 10% to 15% of patients.
Diagnostic Imaging. Apart from the history and physical examination, imaging techniques are the mainstay of diagnosis in Kienb6cKs dis-ease. Posteroanterior and lateral x-rays of the wrist help to determine the presence of avascu-lar necrosis and u1nar variance. X-rays in early Kienb6ck-'s disease may be completely normal. The earliest indication of avascular necrosis on plain radiographs is increased lunate density ac-companied by flattening, but chronic pain will likely* be present before x-ray findings appear.
Computed tomography (CT) has gained wide acceptance in the early diagnosis and evaluation of Kienbock’s disease. Cr delineates the went of lunate sclerosis and collapse better than do plain radiographs.
Bone scintigraphy using Tc-99m phosphate is a highly sensitive, albeit nonspecific, modality for identifying metabolic bone changes. It has a role as a screening tool in patients who have wrist pain of unknown origin and normal radiographs.
While plain x-rays, CT, and bone scans are useful screening tests, magnetic resonance imaging (NM yields a definitive diagnosis. MRI very effectively helps detect early avascular necrosis in various bones, including the lunate, by revealing loss of bone marrow fiat. It can detect abnormalities in the lunate when plain radiographs are normal.
Classification. Uchtman et Al described four stages of Kienbock's disease. Stage I is an acute injury with x-rays showing normal lunate density and structure A compression fracture may exist at this stage but may only be detected with tomography or Cr. In a patient who has wrist pain, limitation of wrist motion, and normal x-rays, the physician must have a high suspicion for stage I or stage 2 Kienbock's disease and should proceed with an additional imaging modality, such as CT or MRI. Stage 2 is characterized by increased radiographic density in the lunate relative to the other carpal bones. The lunate retains its size, shape, and anatomic relationship to the other carpal bones. Stage 3 Kienbock's disease is characterized by lunate collapse and proximal migration of the capitate. Scapholunate dissociation is a prominent feature on an-teroposterior radiographs. Stage 4 disease is characterized by established osteoarthritis of the wrist, with degenerative cysts, subchondral scle-rosis, and joint space narrowing.
Treatment-Usually Operative
Immobilization was initially advocated for all stages of the disease. The results, however, have generally been unsatisfactory, with progressive collapse common! Based on clinical experience, though, immobilization in a cast until symp-toms resolve for stage 1 disease is still reasonable to decrease the vascular injury and allow the lunate to heal.
Patients with negative ulnar variance may benefit from an equalization of the distal articular surfaces of the radius and ulna. Excellent results have been reported with ulnar-lengthening---as in our patient---and radial-shortening osteotomies. These operations should not be used when the lunate has collapsed, as in stage 3 or 4 disease.
In stage 3 disease, triscaphe (scaphoid-trapezium-trapezoid) and scaphocapitate fusion are good treatment options. Good results have been reported with triscaphe fusion This procedure resolves the rotary subluxation of the scaphoid and prevents proximal migration of the distal carpal row.
Salvage procedures for stage 4 disease include proximal row carpeCtomy and wrist arthrodesis. The choice between these two procedures depends on the activity level of the patient Proximal row carpectomy is desirable for patients requiring motion over strength, wrist fusion is the salvage procedure of choice for patients who need strength.
Recognizing Acute injury
Kienbock's disease is rare but must be suspected in patients who have wrist pain, with or without trauma. Physically active people, especially those involved in high-impact loading activities of the wrist, may be at risk for developing Kienbock’s disease.