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Heterotopic ossification of the temporomandibular joint in a burn patient
J Oral Maxillofac
Surg
44:697-699,1966
Hetero topic Ossification of the Temporomandibular Joint in a Burn Patient MITCHELL
M. RUBIN, DMD,* AND GERARD M.
COZZI,DDSt
confinement in bed of two months or more in one study.’ The incidence of heterotopic ossification following severe burns has been estimated at 2 to 3% by Evans,5 3.3% by Kolar and Vrabec,‘j and 13% by Munster et al.* The most common site of heterotopic ossification is the elbow joint, followed by the hip. Rare reports of shoulder, knee, ankle, and wrist ossification also exist, To the authors’ knowledge, there is no previously reported case of heterotopic ossification involving the temporomandibular joint in a burn patient. The earliest sign of calcification is a change, often subtle, in joint motion noticed by the physical therapist, i.e., slight loss of active range of motion or the need for assistance to achieve the range formerly present. This change generally precedes radiographic changes by five days. The deposition in tissue of a solid, inorganic mineral phase that contains calcium and phosphate ions, and is not organized like bone, is called heterotopic calcification. If the mineral phase is deposited in well-formed bone, it is referred to as heterotopic ossification. It has not been established that calcification must precede heterotopic bone formation. In fact, calcification of tissue other than bone usually is not converted to true bone.7 The fact that heterotopic bone may be resorbed after clinical improvement of the condition of the periarticular tissues suggests that some local and humoral alteration is present; it may vary from patient to patient, or patients may respond differently to it. In any event, there must be some individual predilection for the formation of heterotopic bone, since it occurs in only a very small percentage of persons.5
Heterotopic ossification involving joints in burn patients was first described in the English-language literature by Johnson in 1957.’ It is a crippling complication of thermal injury. It may affect any patient with severe burns and is reported to be related to prolonged immobility. Systemic metabolic changes seem to play little part in the etiology of the calcification, and spontaneous resolution is not uncommon.* It is of particular interest that the calcification can occur about joints of which the covering skin was not directly involved in the burn process, and that the patient need not sustain burns that extend down to the capsular structure. These two factors certainly suggest that some alteration in metabolism plays a large role in the production of the periarticular ossification, but no specific chemical alterations in blood values (including serum calcium, phosphorus, and alkaline phosphatase) have been found.3 Injury with bleeding as a result of enthusiastic physiotherapy has been incriminated as the major cause of such bone formation by some authors. More recent work suggests that increased nutritional support regimens, particularly in respect to protein, cause a calciuretic response in burn patients. This iatrogenic mobilization of calcium, together with increased levels of calcium due to injury and bedrest, may precipitate heterotopic ossification.4 Heterotopic bone occurs most often in patients with full-thickness skin loss of 22% or more; thus, it is evident that the extent and depth of the burns are factors. What may be of greater significance, however, is the period of confinement, as heterotopic bone was detected only after periods of Received from the Department of Oral and Maxillofacial Surgery, Nassau County Medical Center, East Meadow, New York. * Chief Resident. t Director of Advanced Training. Address correspondence and reprint requests to Dr. Rubin: 106 Sprucewood Drive, Levittown, NY 11756.
Report of a Case On June 17, 1977, a 17-year-old black man was admitted to the Nassau County Medical Center burn unit. He had sustained second- and third-degree thermal burns on 30% of his body secondary to the ignition of gasoline
0278-2391/86 $0.00 + .25
a97
898
HETEROTOPIC
OSSIFICATION
IN A BURN
PATIENT
FIGURE I (top /cqi). Panoramic radiograph showing preoperative ankylosis of the mandibular condyle. The arrow indicates the region of heterotopic ossification. FIGURE 2 t~ighf). Radiograph showing lack of forward excursion of the right condyle in an open-mouth view. The arrow indicates the condylar region. FIGURE 3 (middle /eff). Panoramic radiograph showing bilateral condylar implants one week after insertion. The patient’s ability to open the mouth and the clearly defined radiolucent joint space are shown. FIGURE 4 (hottom /qfrI. Panoramic radiograph showing ankylosis three years after insertion of condylar implants. The patient’s inability to open the mouth and the bone formation that has obliterated the left joint space are illustrated.
on his clothes. His medical history revealed no abnormalities other than a moderate learning disability. On admission to the hospital his vital signs were as follows: blood pressure, 100170 mm Hg; pulse, 120 beats/minute: respiratory rate, 2Wminute: and temperature 36.4”C. Physical examination revealed a well-developed, well-nourished black man in mild distress. He was normocephalic, and he had a marked anterior, skeletal open bite. There was no evidence of burns or trauma to the head or neck region. No carbonaceous debris was found on the palate or anywhere in the oral cavity. His neck was supple and nontender. Chest examination revealed posterior and anterior thoracic burns. His chest was clear to auscultation bilaterally. Cardiac auscultation demonstrated no murmurs, gallops, or rubs. Abdominal examination revealed a soft, nontender abdomen. The patient had full range of motion in all four extremities. although burns were observed in the axilla and medial aspects of the upper extremities, as well as the groin and inner aspects of both thighs. Results of blood studies at admission were all within normal limits (serum calcium, 8.9 mg/lOO ml; phosphorous, 3.2 mg/lOO ml; and alkaline phosphatase, 112 U/l). Urine analysis showed mild proteinuria.
The patient was admitted to the burn center and was treated initially with Hubbard tank therapy, as well as with topical application of Silverdine. However, his clinical course deteriorated: wound sepsis developed, and he was treated with intravenous antibiotics, to which he responded well. He also had multiple episodes of spiking temperatures and presented a difficult management problem from the standpoint of diet and motivation. He experienced persistent nightmares regarding the burn incident. He often refused to eat or move in bed, and areas of sacral decubitae subsequently developed. His weight and overall condition gradually improved with a carefully supervised diet. He underwent multiple episodes of debridement and skin grafting, and was discharged from the burn center on October 1, 1977, three and a half months after admission. On January 10, 1978, the patient presented to a private oral and maxillofacial surgeon’s office because of complete inability to open his mouth or eat solid food. The patient did not have restricted movement of any other joints. Radiographs of both right and left mandibular condyles were suggestive of ankylosis of the temporomandibular joints (Fig. 1). Bilateral anthroplasty was per-
099
RUBIN AND COZZI
formed, with interpositional placement of Silastic secured to the ramal stumps with bone screws. At surgery, excess bone growth was clearly seen bridging the space between the condyle and the glenoid fossa bilaterally. After surgery, the patient was able to open his mouth approximately 2 cm. A vigorous regimen of oral physiotherapy was begun. The patient remained symptom-free for many months and was then lost to follow-up study. Four years later he presented to the oral and maxillofacial surgery outpatient facility at Nassau County Medical Center with complete inability to open his mouth. Radiographs (Fig. 2) revealed lack of forward excursion of the mandible when open- and closed-mouth views were compared. In November 1982 the silastic implants were found on surgical exploration to be completely encased in new bone and were, therefore, removed. Bilateral condylar implants (Kent prostheses) were inserted and made to articulate with Teflon-coated Proplast glenoid fossa replacements. After surgery, the patient was able to open his mouth approximately 2 cm (Fig. 3). A vigorous regimen of oral physiotherapy was instituted. He remained symptom-free for many months but then discontinued treatment despite encouragement. Three years later the patient returned to the oral and maxillofacial surgery outpatient facility at Nassau County Medical Center because of the inability to open his mouth and a draining sinus tract in the left preauricular area. A panoramic radiograph (Fig. 4) suggested new bone formation filling the space between the mandible and the temporal bone. A sinogram revealed the infection to emanate from the left condylar prosthesis. Staphylococcus Ctwel4.s was cultured from the tract and found to be sensitive to Keflex. This antibiotic was administered for two weeks, at the end of which the drainage had ceased. The left imnlant was removed in April 1985, at which time the os&cation was clearly seen. Two days after surgery the patient started a course of radiation therapy to the left temporomandibular joint area. receiving 2 Gy for five successive days. The patient subsequently remained free of infection and continued to have 1 cm of opening.
Discussion
Evans5 maintained that heterotopic ossification is amenable to resection after the surrounding skin is soft and all granulating areas are healed. He warned that resection should not be performed if there is skin infection in any area and that, optimally, there
should be no proliferating scar tissue. In his study heterotopic bone had not regenerated to its original dimension in any instance after adequate removal. In contrast, Boyd et a1.3 insisted that no surgical removal of periarticular ossification is indicated, as reossification is bound to occur within three months, with greater limitation of movement than previously. Our findings seem to confirm the theory of Boyd et al. that surgical intervention may be of little value in the treatment of heterotopic ossification. Our patient’s lack of cooperation regarding home exercises and appointments for physiotherapy, however, may have enhanced the process of bone deposition. New developments in medical therapeutics may aid in the future treatment of heterotopic ossification in burn patients. For example, the development of diphosphonates, very potent inhibitors of mineralization and bone resorption, has provided an effective way to prevent ectopic calcification.7 Low-dose irradiation, instituted a few days after surgery, has also been advocated to prevent recurrence of ossification in surgically treated joints. Much research into the etiology, prevention, and treatment of this uncommon complication of thermal injury remains to be performed. References I. Johnson JH: Atypical myositis ossificans. J Bone Joint Surg 39A: 189. 1957 2. Munster AM, Bruck HM. Johns LA, et al: Heterotopic calcification following burns: a prospective study. J Trauma 12:1071, 1973 3. Boyd BM Jr, Roberts WM. Miller GR: Periarticular ossification followine burns. South Med J 52: 1048, 1959 4. Heslop JH: Heterotopic periarticular ossification in burns. Burns 8:436. 1982 5. Evans EB: Orthopaedic measures in the treatment of severe burns. J Bone Joint Surg 48A:643, 1966 6. Kolar J, Vrabec R: Periarticular soft-tissue changes as a late consequence of burns. J Bone Joint Surg 41A:l03, 1959 7. Edlich RD, Horowitz JH, Rheuban KS. et al: Heterotopic calcification and ossification in burn patients. Curr Concepts Trauma Care 8:4, 1985
Surg
44:697-699,1966
Hetero topic Ossification of the Temporomandibular Joint in a Burn Patient MITCHELL
M. RUBIN, DMD,* AND GERARD M.
COZZI,DDSt
confinement in bed of two months or more in one study.’ The incidence of heterotopic ossification following severe burns has been estimated at 2 to 3% by Evans,5 3.3% by Kolar and Vrabec,‘j and 13% by Munster et al.* The most common site of heterotopic ossification is the elbow joint, followed by the hip. Rare reports of shoulder, knee, ankle, and wrist ossification also exist, To the authors’ knowledge, there is no previously reported case of heterotopic ossification involving the temporomandibular joint in a burn patient. The earliest sign of calcification is a change, often subtle, in joint motion noticed by the physical therapist, i.e., slight loss of active range of motion or the need for assistance to achieve the range formerly present. This change generally precedes radiographic changes by five days. The deposition in tissue of a solid, inorganic mineral phase that contains calcium and phosphate ions, and is not organized like bone, is called heterotopic calcification. If the mineral phase is deposited in well-formed bone, it is referred to as heterotopic ossification. It has not been established that calcification must precede heterotopic bone formation. In fact, calcification of tissue other than bone usually is not converted to true bone.7 The fact that heterotopic bone may be resorbed after clinical improvement of the condition of the periarticular tissues suggests that some local and humoral alteration is present; it may vary from patient to patient, or patients may respond differently to it. In any event, there must be some individual predilection for the formation of heterotopic bone, since it occurs in only a very small percentage of persons.5
Heterotopic ossification involving joints in burn patients was first described in the English-language literature by Johnson in 1957.’ It is a crippling complication of thermal injury. It may affect any patient with severe burns and is reported to be related to prolonged immobility. Systemic metabolic changes seem to play little part in the etiology of the calcification, and spontaneous resolution is not uncommon.* It is of particular interest that the calcification can occur about joints of which the covering skin was not directly involved in the burn process, and that the patient need not sustain burns that extend down to the capsular structure. These two factors certainly suggest that some alteration in metabolism plays a large role in the production of the periarticular ossification, but no specific chemical alterations in blood values (including serum calcium, phosphorus, and alkaline phosphatase) have been found.3 Injury with bleeding as a result of enthusiastic physiotherapy has been incriminated as the major cause of such bone formation by some authors. More recent work suggests that increased nutritional support regimens, particularly in respect to protein, cause a calciuretic response in burn patients. This iatrogenic mobilization of calcium, together with increased levels of calcium due to injury and bedrest, may precipitate heterotopic ossification.4 Heterotopic bone occurs most often in patients with full-thickness skin loss of 22% or more; thus, it is evident that the extent and depth of the burns are factors. What may be of greater significance, however, is the period of confinement, as heterotopic bone was detected only after periods of Received from the Department of Oral and Maxillofacial Surgery, Nassau County Medical Center, East Meadow, New York. * Chief Resident. t Director of Advanced Training. Address correspondence and reprint requests to Dr. Rubin: 106 Sprucewood Drive, Levittown, NY 11756.
Report of a Case On June 17, 1977, a 17-year-old black man was admitted to the Nassau County Medical Center burn unit. He had sustained second- and third-degree thermal burns on 30% of his body secondary to the ignition of gasoline
0278-2391/86 $0.00 + .25
a97
898
HETEROTOPIC
OSSIFICATION
IN A BURN
PATIENT
FIGURE I (top /cqi). Panoramic radiograph showing preoperative ankylosis of the mandibular condyle. The arrow indicates the region of heterotopic ossification. FIGURE 2 t~ighf). Radiograph showing lack of forward excursion of the right condyle in an open-mouth view. The arrow indicates the condylar region. FIGURE 3 (middle /eff). Panoramic radiograph showing bilateral condylar implants one week after insertion. The patient’s ability to open the mouth and the clearly defined radiolucent joint space are shown. FIGURE 4 (hottom /qfrI. Panoramic radiograph showing ankylosis three years after insertion of condylar implants. The patient’s inability to open the mouth and the bone formation that has obliterated the left joint space are illustrated.
on his clothes. His medical history revealed no abnormalities other than a moderate learning disability. On admission to the hospital his vital signs were as follows: blood pressure, 100170 mm Hg; pulse, 120 beats/minute: respiratory rate, 2Wminute: and temperature 36.4”C. Physical examination revealed a well-developed, well-nourished black man in mild distress. He was normocephalic, and he had a marked anterior, skeletal open bite. There was no evidence of burns or trauma to the head or neck region. No carbonaceous debris was found on the palate or anywhere in the oral cavity. His neck was supple and nontender. Chest examination revealed posterior and anterior thoracic burns. His chest was clear to auscultation bilaterally. Cardiac auscultation demonstrated no murmurs, gallops, or rubs. Abdominal examination revealed a soft, nontender abdomen. The patient had full range of motion in all four extremities. although burns were observed in the axilla and medial aspects of the upper extremities, as well as the groin and inner aspects of both thighs. Results of blood studies at admission were all within normal limits (serum calcium, 8.9 mg/lOO ml; phosphorous, 3.2 mg/lOO ml; and alkaline phosphatase, 112 U/l). Urine analysis showed mild proteinuria.
The patient was admitted to the burn center and was treated initially with Hubbard tank therapy, as well as with topical application of Silverdine. However, his clinical course deteriorated: wound sepsis developed, and he was treated with intravenous antibiotics, to which he responded well. He also had multiple episodes of spiking temperatures and presented a difficult management problem from the standpoint of diet and motivation. He experienced persistent nightmares regarding the burn incident. He often refused to eat or move in bed, and areas of sacral decubitae subsequently developed. His weight and overall condition gradually improved with a carefully supervised diet. He underwent multiple episodes of debridement and skin grafting, and was discharged from the burn center on October 1, 1977, three and a half months after admission. On January 10, 1978, the patient presented to a private oral and maxillofacial surgeon’s office because of complete inability to open his mouth or eat solid food. The patient did not have restricted movement of any other joints. Radiographs of both right and left mandibular condyles were suggestive of ankylosis of the temporomandibular joints (Fig. 1). Bilateral anthroplasty was per-
099
RUBIN AND COZZI
formed, with interpositional placement of Silastic secured to the ramal stumps with bone screws. At surgery, excess bone growth was clearly seen bridging the space between the condyle and the glenoid fossa bilaterally. After surgery, the patient was able to open his mouth approximately 2 cm. A vigorous regimen of oral physiotherapy was begun. The patient remained symptom-free for many months and was then lost to follow-up study. Four years later he presented to the oral and maxillofacial surgery outpatient facility at Nassau County Medical Center with complete inability to open his mouth. Radiographs (Fig. 2) revealed lack of forward excursion of the mandible when open- and closed-mouth views were compared. In November 1982 the silastic implants were found on surgical exploration to be completely encased in new bone and were, therefore, removed. Bilateral condylar implants (Kent prostheses) were inserted and made to articulate with Teflon-coated Proplast glenoid fossa replacements. After surgery, the patient was able to open his mouth approximately 2 cm (Fig. 3). A vigorous regimen of oral physiotherapy was instituted. He remained symptom-free for many months but then discontinued treatment despite encouragement. Three years later the patient returned to the oral and maxillofacial surgery outpatient facility at Nassau County Medical Center because of the inability to open his mouth and a draining sinus tract in the left preauricular area. A panoramic radiograph (Fig. 4) suggested new bone formation filling the space between the mandible and the temporal bone. A sinogram revealed the infection to emanate from the left condylar prosthesis. Staphylococcus Ctwel4.s was cultured from the tract and found to be sensitive to Keflex. This antibiotic was administered for two weeks, at the end of which the drainage had ceased. The left imnlant was removed in April 1985, at which time the os&cation was clearly seen. Two days after surgery the patient started a course of radiation therapy to the left temporomandibular joint area. receiving 2 Gy for five successive days. The patient subsequently remained free of infection and continued to have 1 cm of opening.
Discussion
Evans5 maintained that heterotopic ossification is amenable to resection after the surrounding skin is soft and all granulating areas are healed. He warned that resection should not be performed if there is skin infection in any area and that, optimally, there
should be no proliferating scar tissue. In his study heterotopic bone had not regenerated to its original dimension in any instance after adequate removal. In contrast, Boyd et a1.3 insisted that no surgical removal of periarticular ossification is indicated, as reossification is bound to occur within three months, with greater limitation of movement than previously. Our findings seem to confirm the theory of Boyd et al. that surgical intervention may be of little value in the treatment of heterotopic ossification. Our patient’s lack of cooperation regarding home exercises and appointments for physiotherapy, however, may have enhanced the process of bone deposition. New developments in medical therapeutics may aid in the future treatment of heterotopic ossification in burn patients. For example, the development of diphosphonates, very potent inhibitors of mineralization and bone resorption, has provided an effective way to prevent ectopic calcification.7 Low-dose irradiation, instituted a few days after surgery, has also been advocated to prevent recurrence of ossification in surgically treated joints. Much research into the etiology, prevention, and treatment of this uncommon complication of thermal injury remains to be performed. References I. Johnson JH: Atypical myositis ossificans. J Bone Joint Surg 39A: 189. 1957 2. Munster AM, Bruck HM. Johns LA, et al: Heterotopic calcification following burns: a prospective study. J Trauma 12:1071, 1973 3. Boyd BM Jr, Roberts WM. Miller GR: Periarticular ossification followine burns. South Med J 52: 1048, 1959 4. Heslop JH: Heterotopic periarticular ossification in burns. Burns 8:436. 1982 5. Evans EB: Orthopaedic measures in the treatment of severe burns. J Bone Joint Surg 48A:643, 1966 6. Kolar J, Vrabec R: Periarticular soft-tissue changes as a late consequence of burns. J Bone Joint Surg 41A:l03, 1959 7. Edlich RD, Horowitz JH, Rheuban KS. et al: Heterotopic calcification and ossification in burn patients. Curr Concepts Trauma Care 8:4, 1985