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Radiocapitellar hemiarthroplasty for radiocapitellar arthritis: A report of three cases
Radiocapitellar hemiarthroplasty for radiocapitellar arthritis: A report of three cases Andras Heijink, MD, Bernard F. Morrey, MD, and William P. Cooney, III, MD, Rochester, MN
A
rthritic degeneration of the radiocapitellar joint can be a painful and disabling condition that results from trauma or primary degenerative arthritis. After metallic radial head arthroplasty, there is the potential of degenerative change resulting in an increased contact pressure due to the decrease in contact surface at the radiocapitellar joint.5,6 This potential of degenerative arthritis may be aggravated by disuse osteoporosis of the capitellum in cases of previous excision of the radial head.11 With increasing use of metallic radial head prostheses, this condition of radiocapitellar arthritis can be expected to be seen more frequently.2-5,7 To our knowledge, the use of capitellar resurfacing arthroplasty has not been reported. Three cases are presented in which elbow pain from radiocapitellar arthritis developed owing to longitudinal radioulnar dissociation.9 We report the preliminary results of metallic capitellar resurfacing arthroplasty combined with metalbacked, polyethylene radial head arthroplasty (ie, radiocapitellar hemiarthroplasty).
MATERIALS AND METHODS Three patients have been treated at our institution with custom metallic capitellar resurfacing arthroplasty as part of a radiocapitellar hemiarthroplasty for radiocapitellar arthritis. In all cases, the radiocapitellar arthritis had developed owing to chronic longitudinal radioulnar dissociation. After Institutional Review Board approval was obtained, medical records were reviewed, and each patient was seen in the office for a physical examination and radiographic followup. Elbow function was scored with the Mayo Elbow Performance Score (MEPS).8,10 Radiographs of the elbow were reviewed for degenerative changes and signs of osteopenia of the capitellum, and degenerative changes were graded as previously described.1 Average clinical follow-up was 87 months (range, 25-173 months), and average radiographic follow-up was 83 months (range, 17-173 months). The surgical approach to the lateral aspect of the elbow consisted in a lateral Kocher incision with reflection of the lateral collateral ligament and anterior capsule from the lateral From the Department of Orthopedic Surgery, Mayo Clinic. Reprint requests: William P. Cooney III, MD, Department of Orthopedic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (E-mail: [email protected]). J Shoulder Elbow Surg 2008;17:e12-e15 Copyright ª 2008 by Journal of Shoulder and Elbow Surgery Board of Trustees. 1058-2746/2008/$34.00 doi:10.1016/j.jse.2007.04.009
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epicondyle and lateral aspect of the capitellum. The lateral ulnar collateral ligament was detached in Case 2 because a long-stem radial head replacement was necessary. Preservation of the lateral ulnar collateral ligament was stressed. The preparation of the capitellum was performed after the provisional placement and alignment of the radial head prosthesis so that correct contact and positioning of the capitellum with the radial head could be assured. Alignment was assessed using biplanar fluoroscopy. In patient 3, both metallic radial head replacement and insertion of the capitellar implant were performed as a hemiarthroplasty. In patients 1 and 2, the metallic radial head replacement was already in situ, and the metallic articular component of the radial head prosthesis was replaced with a custom metal-backed, polyethylene articular component, while the stem was left in place. Soft tissue closure consisted of repair of the annular ligament (if divided) and reattachment of the lateral ulnar collateral ligament complex through drill holes to the base of the lateral epicondyle. Patient 2 required a long-stem radial head, and the ulnohumeral ligament, which was released for exposure, was repaired to the distal humerus with a Mitek anchor suture (Mitek Surgical Products, Norwood, MA). A modified Krakow suture was use in each case to tighten the lateral capsule-collateral ligament interval.
CASE REPORTS Patient 1 A 50-year-old, right-handed computer worker sustained a work-related, right-sided comminuted radial head fracture when he fell from a ladder. Radial head excision was performed at that time. Four months later, he experienced ulnar-sided wrist pain due to ulnocarpal abutment, which did not resolve with arthroscopic de´bridement of the triangular fibrocartilage and shortening of the distal ulna. At 31 months after the injury, he presented with ulnocarpal impingement, instability of the distal radioulnar joint, and pain and crepitus at the lateral aspect of the elbow. Radiographic examination showed 5-mm positive ulnar variance at the wrist as a result of proximal migration of the radius and impingement of the radial neck on the capitellum. Treatment consisted of custom monoblock metallic radial head arthroplasty (Small Bone Innovations [SBi], New York, NY), which relieved both elbow and wrist pain. Discomfort and tenderness at the lateral aspect of the elbow and occasionally pain at the dorsoulnar aspect of the wrist developed 1.5 years later. Radiographs of the elbow showed grade II degenerative changes at the capitellum (Figure 1). A bone scan of the elbow showed moderate intense uptake at the lateral aspect of the elbow, suggestive of capitellar degeneration.
Heijink, Morrey, and Cooney III
J Shoulder Elbow Surg Volume 17, Number 2
Figure 1 In these (left) anteroposterior and (right) lateral preoperative radiographs of the elbow of patient 1, the capitellum shows moderate (grade II) degenerative changes. The metallic radial head prosthesis (SBi, New York, NY) appears well aligned to the capitellum, without signs of prosthetic loosening.
Forty-nine months after the metallic radial head arthroplasty, and a little more than 6 years after the initial injury, a custom capitellar resurfacing arthroplasty in combination with revision of the metallic radial head to a metalbacked, polyethylene radial head prosthesis (SBi) was performed. Follow-up at 25 months demonstrated a MEPI of 100 points, an excellent result. There was slight discomfort at the elbow only with heavy activities. Radiographs 17 months postoperatively showed the capitellar prosthesis was well seated with no signs of loosening (Figure 2). The radial head prosthesis appeared well aligned on the capitellar prosthesis. There was neutral variance at the wrist.
Patient 2 A 37-year-old woman, who was right-handed computer worker, sustained a left-sided, comminuted radial head fracture when she fell off a horse. Radial head excision and silastic radial head arthroplasty were performed at that time. Twelve years later, the silastic prosthesis needed to be removed for silicone synovitis and prosthetic loosening. One year after removal of the silastic prosthesis, ulnarsided wrist pain developed. Radiographs of the elbow showed degenerative changes. Radiographs of the wrist showed ulnocarpal abutment due to proximal migration of the radius. Two ulnar shortening procedures failed to relieve the pain and clicking at the elbow and painful swelling at the left wrist. The ulnohumeral joint did not appear symmetric on elbow radiographs, and there was proximal migration of the radius. The wrist radiographs demonstrated arthritis at the distal radioulnar joint. A custom metallic radial head prosthesis (SBi) and a metallic ulnar head prosthesis (SBi) were inserted 25 months after the second ulnar-shortening procedure, with a satisfactory result. Over time, increasing pain and extension limitation at the elbow developed. Radiographs showed excellent placement of the ulnar head and radial head prostheses, but there
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Figure 2 Left, Anteroposterior and (right) lateral radiographs taken 17 months postoperatively of the elbow of patient 1 show that the custom capitellar resurfacing prosthesis (SBi, New York, NY) and the metallic radial head prosthesis (SBi) are well seated and well aligned and show no signs of prosthetic loosening.
was suspicion of grade I degenerative changes at the capitellum. A postoperative bone scan at 6 months showed increased uptake at the capitellum and the lateral epicondyle, suggesting a diagnosis of capitellar erosion. Radiographs of the elbow showed grade I degenerative changes at the capitellum. Thirty-one months after insertion of the metallic radial head prosthesis, revision elbow surgery was performed with custom metal-backed, polyethylene radial head arthroplasty in combination with custom metallic capitellar resurfacing arthroplasty (SBi). The elbow pain completely resolved, and the elbow regained nearly full range of motion. Compared with the preoperative examination, there was mild lateral instability of the elbow that appeared to be associated with laxity of the lateral ulnar collateral ligament. Loosening of the radial component subsequently developed and required a revision with a cemented metalbacked, polyethylene radial head prosthesis. The capitellar prosthesis appeared well seated at that time. Follow-up at 63 months demonstrated a MEPS of 80 points, a good result. Radiographs at 63 months showed the capitellar prosthesis was well seated, with no signs of loosening (Figure 3). The radial head prosthesis appeared well aligned on the capitellar prosthesis. There was neutral variance at the wrist.
Patient 3 A left-handed, professional driver had fallen from a picket fence at age 7 years and sustained a left radial head fracture, which was treated with a cast at the time. He had experienced continuous difficulties using the hand due to pain at the elbow ever since and had perception of bone-on-bone impingement at the elbow. Over the years, radiographic evidence developed of posttraumatic degenerative arthritis of the lateral side of the elbow with tenderness over the lateral aspect of the elbow. A diagnosis of radiocapitellar arthritis
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Heijink, Morrey, and Cooney III
J Shoulder Elbow Surg March/April 2008
changes at the capitellum. A hemiarthroplasty with a custom metal-backed, polyethylene radial head arthroplasty and a custom metallic capitellar resurfacing arthroplasty (Techmedica, Camarillo, CA) was performed (Figure 3). At 173 months of follow-up, the clinical outcome continued to be good. The MEPI was 100 points, an excellent result. The patient works full-time as an associate for a local hotel and is satisfied with the outcome. Fluoroscopic imaging at the time showed the capitellar prosthesis was well seated with no signs of loosening.
DISCUSSION
Figure 3 Left, Anteroposterior and (right) lateral radiographs taken 63 months postoperatively of the elbow of patient 2 show that the custom capitellar resurfacing prosthesis (SBi, New York, NY) and the custom metallic radial head prosthesis (SBi) are well seated and well aligned and show no signs of prosthetic loosening
Figure 4 Photograph of the custom radiocapitellar hemiarthroplasty components that were used in patients 1 and 2 (SBi, New York, NY) shows (left) the capitellar resurfacing prosthesis and (right) the metal-backed, polyethylene radial head prosthesis.
was made, and treatment proceeded with radial head excision with soft tissue interposition arthroplasty. Elbow pain persisted, and during excision of an osteophyte from the radial head, chondromalacia of the capitellum was noted with approximately 1 cm of cartilage loss on the head of the capitellum. Despite resection of the base of the capitellum and drilling down to bone in an attempt to stimulate fibrocartilage growth, there was pain at the proximal radioulnar joint. The patient presented 9 years later with further elbow and wrist pain, with findings of ulnar carpal abutment. Wrist radiographs showed positive ulnar variance of 5 mm. Despite an attempt to advance the interosseous membrane, elbow pain persisted related to radiocapitellar impingement. Radiographs of the elbow showed grade II degenerative
Three cases are reported in which capitellar resurfacing arthroplasty as part of a radiocapitellar hemiarthroplasty was performed for symptomatic radiocapitellar arthritis in the setting of chronic longitudinal radioulnar dissociation. In the first and second patients, there was erosion and softening of the osteopenic capitellum from the metallic radial head prosthesis that led to painful degenerative changes at the capitellum. The capitellum perhaps had been softened because of the long period in which there was no radiocapitellar load. The abutment of the radial stump on the capitellum in patient 1, before the metallic radial head replacement was inserted, may have contributed to damaging the capitellum. In the third patient, there was direct trauma to the capitellum at the time of injury that led to painful degenerative changes of capitellum over time. For all three patients, good objective clinical outcome scores were obtained, and all were satisfied with the result. Patients 2 and 3 returned to work without significant problems. Patient 1 was not able to return to his original work as a carpenter owing to unrelated comorbidity but is able to perform light work without pain. In patient 2, mild lateral instability of the elbow developed postoperatively, likely as a result of the extended surgical approach involving repair of the lateral ulnar collateral ligament that was required for insertion of a long-stemmed radial head prosthesis. She also required subsequent revision of the radial head prosthesis for aseptic loosening, during which the capitellar prosthesis was left untouched. The radial head prosthesis (monoblock) had been in place for 4 years. Revision was performed with a bipolar radial head prosthesis. On radiographic examination, all capitellar prostheses appeared well seated with no signs of prosthetic loosening. In patient 1, there were reactive changes at the lateral humeral epicondyle, likely as a result of unloading due to the capitellar prosthesis. It has been demonstrated that with metallic radial hemiarthroplasty, the radiocapitellar contact area is deceased by an average of 68% compared with the native radiocapitellar joint.6 Naturally, this leads to greater contact pressures compared with the native joint that could predispose the capitellum to degenerative changes. It has also been reported that osteopenic changes after metallic radial head arthroplasty occurred in 78% of cases; the authors attributed this to changes in load transfer. This may be an additional, aggravating factor that produces radiocapitellar arthritis.7 The first and second patients in this report showed the occurrence of degenerative changes after insertion of a metallic radial head prosthesis. In both patients, some degree of osteopenia was present at the time of metallic radial head
J Shoulder Elbow Surg Volume 17, Number 2
arthroplasty. We believe that the osteopenic capitellum, especially when exposed to increased pressures, may undergo degenerative changes relatively quickly. To what extent the higher than usual forces present with longitudinal radioulnar dissociation contribute to erosion of the capitellum and if the change in force transmission due to the metallic radial head prosthesis contributes to the local capitellar cartilage loss and underlying bone degeneration is unknown. We believe that a metallic capitellar resurfacing arthroplasty, combined with a polyethylene metal-backed radial head arthroplasty (ie, radiocapitellar hemiarthroplasty), appears to be a good technique to treat symptomatic radiocapitellar arthritis. We also believe that performing a capitellar resurfacing arthroplasty at the same time of the metallic radial head arthroplasty should be considered when capitellar bone quality is poor. This need can be evaluated radiographically and intraoperatively. We currently recommend an anatomic unipolar design for acute Essex Lopresti injuries, wherein the elbow joint soft tissue anatomy is presumed to be normal. In cases of associated ligament injury at the elbow or chronic radioulnar instability, we recommend a bipolar prosthesis because it is more forgiving when the anatomy is not perfect. REFERENCES
1. Broberg MA, Morrey BF. Results of delayed excision of the radial head after fracture. J Bone Joint Surg Am 1986;68:669-74.
Heijink, Morrey, and Cooney III
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2. Harrington IJ, Sekyi-Out A, Barrington TW, Evans DC, Tuli V. The functional outcome with metallic radial head implants in the treatment of unstable elbow fractures: a long-term review. J Trauma 2001;50:46-52. 3. Harrington IJ, Tountas AA. Replacement of the radial head in the treatment of unstable elbow fractures. Injury 1981;12:405-12. 4. Judet T, Garreau de Loubresse C, Piriou P, Charnley G. A floating prosthesis for radial-head fractures. J Bone Joint Surg Br 1996;78: 244-9. 5. Knight DJ, Rymaszewski LA, Amis AA, Miller JH. Primary replacement of the fractured radial head with a metal prosthesis. J Bone Joint Surg Br 1993;75:572-6. 6. Liew VS, Cooper IC, Ferreira LM, Johnson JA, King GJ. The effect of metallic radial head arthroplasty on radiocapitellar joint contact area. Clin Biomech (Bristol, Avon) 2003;18:115-8. 7. Moro JK, Werier J, MacDermid JC, Patterson SD, King GJ. Arthroplasty with a metal radial head for unreconstructible fractures of the radial head. J Bone Joint Surg Am 2001;83:1201-11. 8. Morrey BF, Adams RA. Semiconstrained arthroplasty for the treatment of rheumatoid arthritis of the elbow. J Bone Joint Surg Am 1992;74:479-90. 9. Trousdale RT, Amadio PC, Cooney WP, Morrey BF. Radio-ulnar dissociation. A review of twenty cases. J Bone Joint Surg Am 1992;74:1486-97. 10. Turchin DC, Beaton DE, Richards RR. Validity of observer-based aggregate scoring systems as descriptors of elbow pain, function, and disability. J Bone Joint Surg Am 1998;80:154-62. 11. Van Riet RP, Van Glabbeek F, Verborgt O, Gielen J. Capitellar erosion caused by a metal radial head prosthesis. A case report. J Bone Joint Surg Am 2004;86:1061-4.
A
rthritic degeneration of the radiocapitellar joint can be a painful and disabling condition that results from trauma or primary degenerative arthritis. After metallic radial head arthroplasty, there is the potential of degenerative change resulting in an increased contact pressure due to the decrease in contact surface at the radiocapitellar joint.5,6 This potential of degenerative arthritis may be aggravated by disuse osteoporosis of the capitellum in cases of previous excision of the radial head.11 With increasing use of metallic radial head prostheses, this condition of radiocapitellar arthritis can be expected to be seen more frequently.2-5,7 To our knowledge, the use of capitellar resurfacing arthroplasty has not been reported. Three cases are presented in which elbow pain from radiocapitellar arthritis developed owing to longitudinal radioulnar dissociation.9 We report the preliminary results of metallic capitellar resurfacing arthroplasty combined with metalbacked, polyethylene radial head arthroplasty (ie, radiocapitellar hemiarthroplasty).
MATERIALS AND METHODS Three patients have been treated at our institution with custom metallic capitellar resurfacing arthroplasty as part of a radiocapitellar hemiarthroplasty for radiocapitellar arthritis. In all cases, the radiocapitellar arthritis had developed owing to chronic longitudinal radioulnar dissociation. After Institutional Review Board approval was obtained, medical records were reviewed, and each patient was seen in the office for a physical examination and radiographic followup. Elbow function was scored with the Mayo Elbow Performance Score (MEPS).8,10 Radiographs of the elbow were reviewed for degenerative changes and signs of osteopenia of the capitellum, and degenerative changes were graded as previously described.1 Average clinical follow-up was 87 months (range, 25-173 months), and average radiographic follow-up was 83 months (range, 17-173 months). The surgical approach to the lateral aspect of the elbow consisted in a lateral Kocher incision with reflection of the lateral collateral ligament and anterior capsule from the lateral From the Department of Orthopedic Surgery, Mayo Clinic. Reprint requests: William P. Cooney III, MD, Department of Orthopedic Surgery, Mayo Clinic, 200 First St SW, Rochester, MN 55905 (E-mail: [email protected]). J Shoulder Elbow Surg 2008;17:e12-e15 Copyright ª 2008 by Journal of Shoulder and Elbow Surgery Board of Trustees. 1058-2746/2008/$34.00 doi:10.1016/j.jse.2007.04.009
e12
epicondyle and lateral aspect of the capitellum. The lateral ulnar collateral ligament was detached in Case 2 because a long-stem radial head replacement was necessary. Preservation of the lateral ulnar collateral ligament was stressed. The preparation of the capitellum was performed after the provisional placement and alignment of the radial head prosthesis so that correct contact and positioning of the capitellum with the radial head could be assured. Alignment was assessed using biplanar fluoroscopy. In patient 3, both metallic radial head replacement and insertion of the capitellar implant were performed as a hemiarthroplasty. In patients 1 and 2, the metallic radial head replacement was already in situ, and the metallic articular component of the radial head prosthesis was replaced with a custom metal-backed, polyethylene articular component, while the stem was left in place. Soft tissue closure consisted of repair of the annular ligament (if divided) and reattachment of the lateral ulnar collateral ligament complex through drill holes to the base of the lateral epicondyle. Patient 2 required a long-stem radial head, and the ulnohumeral ligament, which was released for exposure, was repaired to the distal humerus with a Mitek anchor suture (Mitek Surgical Products, Norwood, MA). A modified Krakow suture was use in each case to tighten the lateral capsule-collateral ligament interval.
CASE REPORTS Patient 1 A 50-year-old, right-handed computer worker sustained a work-related, right-sided comminuted radial head fracture when he fell from a ladder. Radial head excision was performed at that time. Four months later, he experienced ulnar-sided wrist pain due to ulnocarpal abutment, which did not resolve with arthroscopic de´bridement of the triangular fibrocartilage and shortening of the distal ulna. At 31 months after the injury, he presented with ulnocarpal impingement, instability of the distal radioulnar joint, and pain and crepitus at the lateral aspect of the elbow. Radiographic examination showed 5-mm positive ulnar variance at the wrist as a result of proximal migration of the radius and impingement of the radial neck on the capitellum. Treatment consisted of custom monoblock metallic radial head arthroplasty (Small Bone Innovations [SBi], New York, NY), which relieved both elbow and wrist pain. Discomfort and tenderness at the lateral aspect of the elbow and occasionally pain at the dorsoulnar aspect of the wrist developed 1.5 years later. Radiographs of the elbow showed grade II degenerative changes at the capitellum (Figure 1). A bone scan of the elbow showed moderate intense uptake at the lateral aspect of the elbow, suggestive of capitellar degeneration.
Heijink, Morrey, and Cooney III
J Shoulder Elbow Surg Volume 17, Number 2
Figure 1 In these (left) anteroposterior and (right) lateral preoperative radiographs of the elbow of patient 1, the capitellum shows moderate (grade II) degenerative changes. The metallic radial head prosthesis (SBi, New York, NY) appears well aligned to the capitellum, without signs of prosthetic loosening.
Forty-nine months after the metallic radial head arthroplasty, and a little more than 6 years after the initial injury, a custom capitellar resurfacing arthroplasty in combination with revision of the metallic radial head to a metalbacked, polyethylene radial head prosthesis (SBi) was performed. Follow-up at 25 months demonstrated a MEPI of 100 points, an excellent result. There was slight discomfort at the elbow only with heavy activities. Radiographs 17 months postoperatively showed the capitellar prosthesis was well seated with no signs of loosening (Figure 2). The radial head prosthesis appeared well aligned on the capitellar prosthesis. There was neutral variance at the wrist.
Patient 2 A 37-year-old woman, who was right-handed computer worker, sustained a left-sided, comminuted radial head fracture when she fell off a horse. Radial head excision and silastic radial head arthroplasty were performed at that time. Twelve years later, the silastic prosthesis needed to be removed for silicone synovitis and prosthetic loosening. One year after removal of the silastic prosthesis, ulnarsided wrist pain developed. Radiographs of the elbow showed degenerative changes. Radiographs of the wrist showed ulnocarpal abutment due to proximal migration of the radius. Two ulnar shortening procedures failed to relieve the pain and clicking at the elbow and painful swelling at the left wrist. The ulnohumeral joint did not appear symmetric on elbow radiographs, and there was proximal migration of the radius. The wrist radiographs demonstrated arthritis at the distal radioulnar joint. A custom metallic radial head prosthesis (SBi) and a metallic ulnar head prosthesis (SBi) were inserted 25 months after the second ulnar-shortening procedure, with a satisfactory result. Over time, increasing pain and extension limitation at the elbow developed. Radiographs showed excellent placement of the ulnar head and radial head prostheses, but there
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Figure 2 Left, Anteroposterior and (right) lateral radiographs taken 17 months postoperatively of the elbow of patient 1 show that the custom capitellar resurfacing prosthesis (SBi, New York, NY) and the metallic radial head prosthesis (SBi) are well seated and well aligned and show no signs of prosthetic loosening.
was suspicion of grade I degenerative changes at the capitellum. A postoperative bone scan at 6 months showed increased uptake at the capitellum and the lateral epicondyle, suggesting a diagnosis of capitellar erosion. Radiographs of the elbow showed grade I degenerative changes at the capitellum. Thirty-one months after insertion of the metallic radial head prosthesis, revision elbow surgery was performed with custom metal-backed, polyethylene radial head arthroplasty in combination with custom metallic capitellar resurfacing arthroplasty (SBi). The elbow pain completely resolved, and the elbow regained nearly full range of motion. Compared with the preoperative examination, there was mild lateral instability of the elbow that appeared to be associated with laxity of the lateral ulnar collateral ligament. Loosening of the radial component subsequently developed and required a revision with a cemented metalbacked, polyethylene radial head prosthesis. The capitellar prosthesis appeared well seated at that time. Follow-up at 63 months demonstrated a MEPS of 80 points, a good result. Radiographs at 63 months showed the capitellar prosthesis was well seated, with no signs of loosening (Figure 3). The radial head prosthesis appeared well aligned on the capitellar prosthesis. There was neutral variance at the wrist.
Patient 3 A left-handed, professional driver had fallen from a picket fence at age 7 years and sustained a left radial head fracture, which was treated with a cast at the time. He had experienced continuous difficulties using the hand due to pain at the elbow ever since and had perception of bone-on-bone impingement at the elbow. Over the years, radiographic evidence developed of posttraumatic degenerative arthritis of the lateral side of the elbow with tenderness over the lateral aspect of the elbow. A diagnosis of radiocapitellar arthritis
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Heijink, Morrey, and Cooney III
J Shoulder Elbow Surg March/April 2008
changes at the capitellum. A hemiarthroplasty with a custom metal-backed, polyethylene radial head arthroplasty and a custom metallic capitellar resurfacing arthroplasty (Techmedica, Camarillo, CA) was performed (Figure 3). At 173 months of follow-up, the clinical outcome continued to be good. The MEPI was 100 points, an excellent result. The patient works full-time as an associate for a local hotel and is satisfied with the outcome. Fluoroscopic imaging at the time showed the capitellar prosthesis was well seated with no signs of loosening.
DISCUSSION
Figure 3 Left, Anteroposterior and (right) lateral radiographs taken 63 months postoperatively of the elbow of patient 2 show that the custom capitellar resurfacing prosthesis (SBi, New York, NY) and the custom metallic radial head prosthesis (SBi) are well seated and well aligned and show no signs of prosthetic loosening
Figure 4 Photograph of the custom radiocapitellar hemiarthroplasty components that were used in patients 1 and 2 (SBi, New York, NY) shows (left) the capitellar resurfacing prosthesis and (right) the metal-backed, polyethylene radial head prosthesis.
was made, and treatment proceeded with radial head excision with soft tissue interposition arthroplasty. Elbow pain persisted, and during excision of an osteophyte from the radial head, chondromalacia of the capitellum was noted with approximately 1 cm of cartilage loss on the head of the capitellum. Despite resection of the base of the capitellum and drilling down to bone in an attempt to stimulate fibrocartilage growth, there was pain at the proximal radioulnar joint. The patient presented 9 years later with further elbow and wrist pain, with findings of ulnar carpal abutment. Wrist radiographs showed positive ulnar variance of 5 mm. Despite an attempt to advance the interosseous membrane, elbow pain persisted related to radiocapitellar impingement. Radiographs of the elbow showed grade II degenerative
Three cases are reported in which capitellar resurfacing arthroplasty as part of a radiocapitellar hemiarthroplasty was performed for symptomatic radiocapitellar arthritis in the setting of chronic longitudinal radioulnar dissociation. In the first and second patients, there was erosion and softening of the osteopenic capitellum from the metallic radial head prosthesis that led to painful degenerative changes at the capitellum. The capitellum perhaps had been softened because of the long period in which there was no radiocapitellar load. The abutment of the radial stump on the capitellum in patient 1, before the metallic radial head replacement was inserted, may have contributed to damaging the capitellum. In the third patient, there was direct trauma to the capitellum at the time of injury that led to painful degenerative changes of capitellum over time. For all three patients, good objective clinical outcome scores were obtained, and all were satisfied with the result. Patients 2 and 3 returned to work without significant problems. Patient 1 was not able to return to his original work as a carpenter owing to unrelated comorbidity but is able to perform light work without pain. In patient 2, mild lateral instability of the elbow developed postoperatively, likely as a result of the extended surgical approach involving repair of the lateral ulnar collateral ligament that was required for insertion of a long-stemmed radial head prosthesis. She also required subsequent revision of the radial head prosthesis for aseptic loosening, during which the capitellar prosthesis was left untouched. The radial head prosthesis (monoblock) had been in place for 4 years. Revision was performed with a bipolar radial head prosthesis. On radiographic examination, all capitellar prostheses appeared well seated with no signs of prosthetic loosening. In patient 1, there were reactive changes at the lateral humeral epicondyle, likely as a result of unloading due to the capitellar prosthesis. It has been demonstrated that with metallic radial hemiarthroplasty, the radiocapitellar contact area is deceased by an average of 68% compared with the native radiocapitellar joint.6 Naturally, this leads to greater contact pressures compared with the native joint that could predispose the capitellum to degenerative changes. It has also been reported that osteopenic changes after metallic radial head arthroplasty occurred in 78% of cases; the authors attributed this to changes in load transfer. This may be an additional, aggravating factor that produces radiocapitellar arthritis.7 The first and second patients in this report showed the occurrence of degenerative changes after insertion of a metallic radial head prosthesis. In both patients, some degree of osteopenia was present at the time of metallic radial head
J Shoulder Elbow Surg Volume 17, Number 2
arthroplasty. We believe that the osteopenic capitellum, especially when exposed to increased pressures, may undergo degenerative changes relatively quickly. To what extent the higher than usual forces present with longitudinal radioulnar dissociation contribute to erosion of the capitellum and if the change in force transmission due to the metallic radial head prosthesis contributes to the local capitellar cartilage loss and underlying bone degeneration is unknown. We believe that a metallic capitellar resurfacing arthroplasty, combined with a polyethylene metal-backed radial head arthroplasty (ie, radiocapitellar hemiarthroplasty), appears to be a good technique to treat symptomatic radiocapitellar arthritis. We also believe that performing a capitellar resurfacing arthroplasty at the same time of the metallic radial head arthroplasty should be considered when capitellar bone quality is poor. This need can be evaluated radiographically and intraoperatively. We currently recommend an anatomic unipolar design for acute Essex Lopresti injuries, wherein the elbow joint soft tissue anatomy is presumed to be normal. In cases of associated ligament injury at the elbow or chronic radioulnar instability, we recommend a bipolar prosthesis because it is more forgiving when the anatomy is not perfect. REFERENCES
1. Broberg MA, Morrey BF. Results of delayed excision of the radial head after fracture. J Bone Joint Surg Am 1986;68:669-74.
Heijink, Morrey, and Cooney III
e15
2. Harrington IJ, Sekyi-Out A, Barrington TW, Evans DC, Tuli V. The functional outcome with metallic radial head implants in the treatment of unstable elbow fractures: a long-term review. J Trauma 2001;50:46-52. 3. Harrington IJ, Tountas AA. Replacement of the radial head in the treatment of unstable elbow fractures. Injury 1981;12:405-12. 4. Judet T, Garreau de Loubresse C, Piriou P, Charnley G. A floating prosthesis for radial-head fractures. J Bone Joint Surg Br 1996;78: 244-9. 5. Knight DJ, Rymaszewski LA, Amis AA, Miller JH. Primary replacement of the fractured radial head with a metal prosthesis. J Bone Joint Surg Br 1993;75:572-6. 6. Liew VS, Cooper IC, Ferreira LM, Johnson JA, King GJ. The effect of metallic radial head arthroplasty on radiocapitellar joint contact area. Clin Biomech (Bristol, Avon) 2003;18:115-8. 7. Moro JK, Werier J, MacDermid JC, Patterson SD, King GJ. Arthroplasty with a metal radial head for unreconstructible fractures of the radial head. J Bone Joint Surg Am 2001;83:1201-11. 8. Morrey BF, Adams RA. Semiconstrained arthroplasty for the treatment of rheumatoid arthritis of the elbow. J Bone Joint Surg Am 1992;74:479-90. 9. Trousdale RT, Amadio PC, Cooney WP, Morrey BF. Radio-ulnar dissociation. A review of twenty cases. J Bone Joint Surg Am 1992;74:1486-97. 10. Turchin DC, Beaton DE, Richards RR. Validity of observer-based aggregate scoring systems as descriptors of elbow pain, function, and disability. J Bone Joint Surg Am 1998;80:154-62. 11. Van Riet RP, Van Glabbeek F, Verborgt O, Gielen J. Capitellar erosion caused by a metal radial head prosthesis. A case report. J Bone Joint Surg Am 2004;86:1061-4.