Stabilizing Effects of a Particulate Demineralized Bone Matrix in the L4 Interbody Space with and without PEEK Cage - A Literature Review and Preliminary Results of a Cadaveric Biomechanical Study.

We reviewed the biological elements supporting the usefulness of a specifically designed particulate form of demineralized bone matrix (DBM) with spinal fusion, and report some limitations of its use described in the medical literature and in the interbody space using a cadaveric biomechanical model. A literature review and description of the techniques used to augment spinal fusion are presented, including a more thorough review of recent findings of cadaveric biomechanical flexibility studies using DBM alone at different percentage fills of the existing disc space and DBM with a polyetheretherketone (PEEK) interbody cage. The need for DBM was established by reviewing limitations of autografts and allografts in spinal fusion. Demineralized bone matrix used alone did not increase stability post discectomy at L4-L5, but was demonstrated to exhibit satisfactory stability when used with a PEEK interbody cage. There may be a future role for DBM that hardens and fills disc space more rigidly, overcoming this limitation to its use.

[The surgeon as a hand patient: the clinical and psychological impact of hand and wrist fractures]. / Chirurgen als Hand-Patienten : Klinische und psychologische Auswirkungen von Hand- und Handgelenkfrakturen.

To gain insight into the management of patients with hand and wrist injuries, a series of clinical and psychological analyses was performed on 9 surgeons, each of whom underwent operative fixation of a hand or wrist fracture. The results of these analyses suggest that the functional outcome after hand surgery was affected by the surgeons' personality, motivation, and ability to accept and adapt to the injury, the nature of the injury, and the importance of the hand to the surgeons' careers. Surgeons are highly motivated and compulsive individuals who consider their career involvement a major source of identity and self-worth. Most returned to their operative duties ahead of the schedule set by their hand surgeons (average, 25 days after surgery), regarded their injuries as a positive challenge, and changed their lifestyles after injury to protect their hands.

The effect of nucleus pulposus crosslinking and glycosaminoglycan degradation on disc mechanical function.

Altered mechanical loading, secondary to biochemical changes in the nucleus pulposus, is a potential mechanism in disc degeneration. An understanding of the role of this altered mechanical loading is only possible by separating the mechanical and biological effects of early nucleus pulposus changes. The objective of this study was to quantify the mechanical effect of decreased glycosaminoglycans (GAG) and increased crosslinking in the nucleus pulposus using in vitro rat lumbar discs. Following initial mechanical testing the discs were injected according to the four treatment groups: PBS control, chondroitinase-ABC (ChABC) for GAG degradation, genipin (Gen) for crosslinking, or a combination of chondroitinase and genipin (ChABC+Gen). After treatment the discs were again mechanically tested, followed by histology or biochemistry. Neutral zone mechanical properties were changed by approximately 20% for PBS, ChABC, and ChABC+Gen treatments (significant only for PBS in a paired comparison). These trends were reversed with genipin crosslinking alone. With ChABC treatment the effective compressive modulus increased and the GAG content decreased; with the combination of ChABC+Gen the mechanics and GAG content were unchanged. Degradation of nucleus pulposus GAG alters disc axial mechanics, potentially contributing to the degenerative cascade. Crosslinking is unlikely to contribute to degeneration, but may be a potential avenue of treatment.

Interspinous bursitis in an athlete.

We present a case of L2/3 interspinous bursitis treated with extraspinal injections. No previous investigations have used fluoroscopically guided spinal injections to confirm the clinical relevance of the MRI features of this type of bursae. Autopsy studies have revealed an increased incidence of interspinous lumbar bursal cavities with advancing age. Afflicted patients present with localised, midline lower lumbar pain exacerbated by extension. In young athletes these symptoms can mimic spondylolysis. MRI is useful in detecting soft-tissue injury of the posterior elements. Fluoroscopically guided diagnostic and therapeutic extraspinal injections can be used for confirmation and treatment of pain from such bursae.

Primary osteosarcoma of the distal femur in two consecutive brothers.

The following report describes two consecutive brothers from a nonimmigrant family, with no identifiable predisposing factors, who presented with osteosarcomas of their distal femurs, one at the age of 18 years and the other at the age of 21 years. Until a cost-effective program is developed to screen for osteosarcoma, a detailed family history should be obtained from every new patient with osteosarcoma and parents should be urged to schedule early evaluations of siblings with complaints of painful extremities. Increased frequency of cytogenetic studies to screen for genetic abnormalities in patients with osteosarcoma is recommended to help elucidate the cause of osteosarcoma.

Osteochondromas of the distal aspect of the tibia or fibula. Natural history and treatment.

BACKGROUND: There is little information on the natural history or treatment of osteochondromas arising from the distal aspect of either the tibia or the fibula. It is believed that there is a risk of deformation of the ankle if these exostoses are left untreated or if the physis or neurovascular structures are injured during operative intervention. METHODS: We reviewed the records of twenty-three patients who had been treated for osteochondroma of the distal aspect of the tibia or fibula between 1980 and 1996. Four of the patients had hereditary multiple cartilaginous exostoses. There were seventeen male and six female patients, and the average age at the time of presentation was sixteen years (range, eight to forty-eight years). RESULTS: Preoperative radiographs showed evidence of plastic deformation of the fibula in eleven patients who had a large osteochondroma. Four patients elected not to have an operation. The tumor was excised in nineteen patients. Postoperatively, all nineteen patients had a Musculoskeletal Tumor Society score of 100 percent for function of the lower extremity with pain-free symmetrical and unrestricted motion of the ankle at the latest follow-up examination. Partial remodeling of the tibia and fibula gradually diminished the asymmetry of the ankles in all nineteen operatively managed patients; however, the remodeling was most complete in the younger patients. Pronation deformities of the ankle did not change after excision of the tumor. Complications of operative treatment included four recurrences (only three of which were symptomatic), one sural neuroma, one superficial wound infection, and one instance of growth arrest of the distal aspects of the tibia and fibula. CONCLUSIONS: Osteochondromas of the distal and lateral aspects of the tibia were more often symptomatic than those of the distal aspect of the fibula; they most commonly occurred in the second decade of life with ankle pain, a palpable mass, and unrestricted ankle motion. Untreated or partially excised lesions in skeletally immature patients may become larger and cause plastic deformation of the tibia and fibula and a pronation deformity of the ankle. Ideally, operative intervention should be delayed until skeletal maturity, but, in symptomatic patients, partial excision preserving the physis may be necessary for the relief of symptoms and the prevention of progressive ankle deformity. However, partial excision is associated with a high rate of recurrence, so a close follow-up is required. Skeletally mature patients who are symptomatic may require excision of the tumor.

Retrograde nailing of femur fractures in patients with myelopathy and who are nonambulatory.

The authors studied 10 consecutive patients with closed femoral shaft or supracondylar fractures who were nonambulatory and who were treated by reamed retrograde intramedullary nailing via an intercondylar notch approach. The study consisted of five women and five men with an average age of 60.7 years (range, 40-89 years). Six patients had spinal cord lesions, one had a brain injury, one had cerebral palsy, one had multiple sclerosis, and one had progressive myelopathy. Three fractures were supracondylar, and seven fractures involved the mid-distal diaphysis. The average time of surgery was 110 minutes (range, 70-225 minutes) with an average estimated blood loss of 288 mL (range, 150-400 mL). There were two postoperative deaths (at 15 days and 2 months, respectively) after the procedure that were attributable to pneumonia. The remaining eight patients were observed for an average of 13 months (range, 6-20 months) after surgery. All fractures healed as evaluated radiographically. Retrograde intramedullary nailing is a simple, safe, and effective alternative to nonoperative treatment for femoral shaft or supracondylar fractures in patients who are nonambulatory. Stabilization by this method allows fracture healing and rapid return of patients to their previous level of function. There were no nonunions, malunions, significant shortening, implant failure, or wound infections.

Reattachment of the migrated ununited greater trochanter after revision hip arthroplasty: the abductor slide technique. A review of four cases.

BACKGROUND: Proximal migration of the ununited greater trochanter following total hip arthroplasty may produce pain and substantial functional disability. Successful reattachment of the migrated fragment is difficult following multiple hip procedures. The purpose of this report is to describe four patients in whom a severely migrated trochanteric fragment was reattached successfully with a modified Charnley-Harris wiring technique after subperiosteal advancement of the abductor muscles from their origin on the iliac wing. METHODS: This series consisted of one man and three women with an average age of sixty years (range, fifty-one to sixty-eight years) at the time of the index procedure. The patients were followed for an average of eighty-one months (range, fifty-five to ninety-six months). All patients had undergone mobilization of the abductor muscles based on the superior gluteal neurovascular pedicle to aid with trochanteric reattachment, and all had undergone prior hip operations (average, two). Advancement of the abductor muscles was achieved through a separate transverse curvilinear incision over the iliac crest, and subperiosteal releases of the entire origins of the gluteus minimus, medius, and maximus muscles from the ilium were performed. RESULTS: Roentgenographic union of the trochanteric fragment occurred in all four patients. There were three excellent functional outcomes (Harris hip scores of 90, 94, and 96 points) and one fair functional outcome (76 points). The average improvement in the Harris hip score was 47.5 points (range, 35 to 58 points). Two patients continued to have a mild or moderate Trendelenburg gait postoperatively. Two patients had heterotopic bone formation of no clinical importance. CONCLUSIONS: Use of this technique resulted in union of the greater trochanter, pain relief, and decreased functional disability without major complications in these four patients. More widespread use of this technique may be indicated for the treatment of symptomatic non-union of the greater trochanter when the fragment cannot be reattached to its anatomical location with the hip in less than approximately 20 degrees of abduction.

Treatment of triplane fractures of the head of the proximal phalanx.

We report the morphology and treatment of 2 cases of a triplane intra-articular bicondylar fracture of the head of the proximal phalanx. Fracture lines in the coronal, sagittal, and transverse planes characterize this fracture, making it highly unstable. Open reduction and internal fixation using two 1.5-mm interfragmentary screws oriented in a dorsal to volar direction resulted in anatomic restoration of the articular surfaces and satisfactory functional results. In 1 case, autogenous cancellous bone graft was harvested from the ipsilateral radial styloid to support the articular fragments.

Wire-loop fixation of volar displaced osteochondral fractures of the distal radius.

We describe the technique of wire-loop fixation to treat 4 young men with a unique variant of Melone's type 4 articular fracture of the volar lunate facet, characterized by a displaced rotated articular fragment supported by a limited amount of subchondral bone. This is an unusual injury that threatens the integrity of both the radiocarpal and distal radioulnar joints. It is the result of a compressive force to the wrist and may require trispiral computed tomography for delineation. Open reduction and internal fixation is recommended to maintain stability and articular congruity. The displaced volar-articular fragment, however, may be relatively small; therefore, direct manipulation could lead to soft tissue stripping and osteonecrosis. We have found the technique of wire-loop fixation to be a simple, reproducible, and effective alternative method of internal fixation for these difficult fractures. Malunion, nonunion, loss of fixation, tendon rupture, infection, arthrosis, or pain caused by hardware has not occurred. Use of this technique is not recommended in patients with osteoporotic bone.

Septic arthritis and osteomyelitis of the wrist: reconstruction with a vascularized fibular graft.

A case of spontaneous staphylococcus arthritis of the wrist with associated carpal and distal radius osteomyelitis is reported. Following sequential debridements and a 6-week course of parenteral antibiotics, an extensive defect was bridged with a vascularized fibular autograft to achieve a successful fusion. There was no donor site morbidity or recurrent infection. Follow-up radiographs 41 months later demonstrated complete incorporation and hypertrophy of the graft.

The surgeon as a hand patient: the clinical and psychological impact of hand and wrist fractures.

To gain insight into the management of patients with hand and wrist injuries, a series of clinical and psychological analyses was performed on 9 surgeons, each of whom underwent operative fixation of a hand or wrist fracture. The results of these analyses suggest that the functional outcome after hand surgery was affected by the surgeons' personality, motivation, and ability to accept and adapt to the injury; the nature of the injury; and the importance of the hand to the surgeons' careers. Surgeons are highly motivated and compulsive individuals who consider their career involvement a major source of identity and self-worth. Most returned to their operative duties ahead of the schedule set by their hand surgeons (average, 25 days after surgery), regarded their injuries as a positive challenge, and changed their lifestyles after injury to protect their hands.

Chronic lymphocytic leukemia presenting as pyogenic arthritis of the proximal interphalangeal joint.

A 66-year-old woman was seen and treated for a chronic lymphocystic leukemic infiltrate of a proximal interphalangeal joint, which presented with clinical and radiologic signs consistent with a pyogenic arthritis.

Probing the bimolecular interactions of parathyroid hormone with the human parathyroid hormone/parathyroid hormone-related protein receptor. 1. Design, synthesis and characterization of photoreactive benzophenone-containing analogs of parathyroid hormone.

Parathyroid hormone (PTH) regulates calcium and phosphate metabolism through a G-protein-coupled receptor which is shared with PTH-related protein (PTHrP). Therefore, structure-activity studies of PTH and PTHrP with their common receptor provide an unusual opportunity to examine the structural elements in the two hormones and their common receptor which are involved in the expression of biological activity. Our approach to studying the nature of the bimolecular interface between hormone and receptor is to use a series of specially designed photoreactive benzophenone- (BP-) containing PTH analogs in "photoaffinity scanning" of the PTH/PTHrP receptor. In this report we describe a series of BP-containing agonists and antagonists which have been synthesized by solid-phase methodology and characterized physiocochemically and biologically. Each of the 12 analogs contains a single BP moiety at a different defined position. Examples of BP-containing agonists prepared and studied in human osteogenic sarcoma Saos-2/B-10 cells are [Nle8,18,Lys13(epsilon-pBZ2),L-2-Nal23,Tyr34]bPTH(1-34 )NH2(K13)(Kb = 13 nM; Km = 2.7 nM) and [Nle8,18,L-Bpa23,Tyr34[bPTH(1-34)NH2(L-Bpa23) (Kb = 42 nM; Km = 8.5 nM). Another BP-containing analog, [Nle8,18,D-2-Nal12,Lys13(epsilon-pBZ2),L-2-Nal23 ,Tyr34]bPTH(7-34)NH2, was a potent antagonist (Kb = 95 nM; Ki = 72 nM). The amino acids substituted by residues carrying the BP moiety span the biologically active domain of the hormone (Phe7, Gly12, Lys13, Trp23, and Lys26). Analysis of photo-cross-linked conjugates of PTH/PTHrP receptor with BP-containing PTH analogs should help to identify the "contact points" between ligand and receptor.