Preliminary clinical experience of robot-assisted surgery in treatment with genioplasty

Genioplasty is the main way to treat diseases such as chin asymmetry, dysplasia and overdevelopment, which involve the three-dimensional direction abnormalities of the chin. Since this kind of surgery mainly uses intraoral incisions, the narrow surgical field of intraoral incisions and the surrounding important neurovascular tissues make it easy for complications, to occur during the osteotomy process, which results in greater surgical risks. The first craniofacial-plastic surgical robot (CPSR-I) system is developed to complete the precise positioning and improve the surgeon's force perception ability. The Kalman filtering method is adopted to reduce the interference of sensor signal noise. An adaptive fuzzy control system, which has strong robustness and adaptability to the environment, is designed to improve the stability of robot-assisted surgical operations. To solve the problem of the depth perception, we propose an automatic bone drilling control strategy that combines position and force conditions to ensure that the robot can automatically stop when the bone is penetrated. On the basis of model surgery and animal experiments, preliminary experiments were carried out clinically. Based on the early results of 6 patients, the robot-assisted approach appears to be a safe and effective strategy for genioplasty.

Unicompartmental knee arthroplasty, is it superior to high tibial osteotomy in treating unicompartmental osteoarthritis? A meta-analysis and systemic review

BACKGROUND

Debate remains whether high tibial osteotomy (HTO) or unicompartmental knee arthroplasty (UKA) is more beneficial for the treatment of unicompartmental knee osteoarthritis. The purpose of this study was to compare the functional results, knee scores, activity levels, and complications between the two procedures.

METHODS

We performed a systematic review of published literature from August 1982 through January 2017. Fifteen papers reporting three prospective randomized trials were subjected to a meta-analysis.

RESULTS

No significant difference between the two groups was noted with respect to free walking (velocity), knee score, deterioration of the contralateral or patellofemoral knee, or revision rate and total knee arthroplasty. However, UKA produced better outcomes compared to HTO in terms of the functional results, pain assessment, and complications, although patients who underwent HTO tended to have slightly better range of motion.

CONCLUSIONS

Valgus HTO provides better physical activity for younger patients whereas UKA is more suitable for older patients due to shorter rehabilitation time and faster functional recovery. Although UKA patients tended to have improved overall long-term outcomes, which may be due to accurate indications and patient selection, both treatment options yielded pleasing results. Therefore, we are unable to conclude that either method is superior.

[Intraoperative quality management modalities in head and neck surgery]

Immediate intraoperative control via suitable imaging techniques is necessary to achieve the best possible surgical outcome. Intraoperative imaging increases patient safety, offers the surgeon direct support in challenging anatomic regions, and affords the possibility of direct correction with a reduced rate of corrective surgery. The procedures are based on cone beam computed tomography (CBCT), endoscopy, or navigation-assisted surgery. This article describes available intraoperative quality management modalities for fracture management and tumor treatment in the field of head and neck surgery.

Postoperative accuracy analysis of three-dimensional corrective osteotomy for cubitus varus deformity with a custom-made surgical guide based on computer simulation

BACKGROUND

For correction of cubitus varus deformity resulting from supracondylar fracture of the humerus, we developed an operative method with use of a custom-made surgical guide, designed on the basis of 3-dimensional (3D) computer simulation with computed tomography data. The purpose of this study was to investigate the postoperative accuracy of this system in clinical cases.

METHODS

Subjects included 17 consecutive patients (13 males and 4 females) with cubitus varus deformity after supracondylar fracture. Patients underwent 3D corrective osteotomy with use of a custom-made surgical guide. Postoperative computed tomography scan was performed after bone union diagnosis on plain radiographs, and postoperative 3D bone models were compared with preoperative simulation by surface registration technique. In addition, we evaluated radiographic parameters (humerus-elbow-wrist angle and tilting angle) and range of elbow motion at the most recent follow-up.

RESULTS

Mean errors in 3D corrective osteotomy were 0.6° ± 0.7° in varus-valgus rotation, 0.8° ± 1.3° in flexion-extension rotation, 2.9° ± 2.8° in internal-external rotation, 1.7 ± 1.8 mm in anterior-posterior translation, 1.3 ± 1.8 mm in lateral-medial translation, and 7.1 ± 6.3 mm in proximal-distal translation. The mean humerus-elbow-wrist angle on plain radiographs of the affected side was 15° in varus before surgery and improved to 6° in valgus after surgery. The mean tilting angle of the affected side was 31° before surgery and improved to 40° after surgery.

CONCLUSION

The 3D correction of cubitus varus deformity was performed accurately within the allowable error limits.

Biomechanical optimization of different fixation modes for a proximal femoral L-osteotomy

BACKGROUND

Numerous proposed surgical techniques have had minimal success in managing greater trochanter overgrowth secondary to retarded growth of the femoral capital epiphysis. For reconstruction of residual hip deformities, a novel type of proximal femur L-osteotomy was performed with satisfactory results. Although the clinical outcome was good, the biomechanical characteristics of the femur after such an osteotomy have not been clearly elucidated. Therefore, this study presents a three dimensional finite element analysis designed to understand the mechanical characteristics of the femur after the L-osteotomy.

METHODS

A patient with left hip dysplasia was recruited as the study model for L-osteotomy. The normal right hip was used as a reference for performing the corrective surgery. Four FEA models were constructed using different numbers of fixation screws but the same osteotomy lengths together with four FEA models with the same number of fixation screws but different osteotomy lengths. The von Mises stress distributions and femoral head displacements were analyzed and compared.

RESULTS

The results revealed the following: 1). The fixation devices (plate and screws) sustained most of the external loading, and the peak value of von Mises stress on the fixation screws decreased with an increasing number of screws. 2). Additional screws are more beneficial on the proximal segment than on the distal segment for improving the stability of the postoperative femur. 3). The extent of osteotomy should be limited because local stress might be concentrated in the femoral neck region with increasing length of the L-osteotomy.

CONCLUSION

Additional screw placement on the proximal segment improves stability in the postoperative femur. The cobra-type plate with additional screw holes in the proximal area might improve the effectiveness of L-osteotomies.

Construction of a standard test assembly for controlled laser studies in tissues: preliminary study on human bone material

The aim of the study is the construction of a test assembly, which facilitates objective, comparative studies on the cutting performance of lasers in hard tissue. To ensure the applicability of our own construction for the reproducible performance of laser incisions in hard tissue, eleven freshly extracted blocks (2x1.5 cm2) of human bone were prepared with a Er,Cr:YSGG laser by using a handheld handpiece, respectively, using the constructed device for a standardized cutting. A total of 44 cuts were executed. The specimen were then histologically evaluated. The standard test assembly met the requirements concerning the provision of objective results. The findings of the histological evaluation prove the reproducibility of the results. The standard test assembly presented in this paper facilitates comparative studies of different laser systems by reducing subjective influence on the preparation to a minimum. The results of this preliminary study show that the precision of the guiding instrument for laser cutting reduces the error of cut width by 50-fold, from 50 to 1 microm.

Decision making regarding Smith-Petersen vs. pedicle subtraction osteotomy vs. vertebral column resection for spinal deformity

STUDY DESIGN

Author experience and literature review.

OBJECTIVES

To investigate and discuss decision-making on when to perform a Smith-Petersen osteotomy as opposed to a pedicle subtraction procedure and/or a vertebral column resection.

SUMMARY OF BACKGROUND DATA

Articles have been published regarding Smith-Petersen osteotomies, pedicle subtraction procedures, and vertebral column resections. Expectations and complications have been reviewed. However, decision-making regarding which of the 3 procedures is most useful for a particular spinal deformity case is not clearly investigated.

METHODS

Discussed in this manuscript is the author's experience and the literature regarding the operative options for a fixed coronal or sagittal deformity.

RESULTS

There are roles for Smith-Petersen osteotomy, pedicle subtraction, and vertebral column resection. Each has specific applications and potential complications.

CONCLUSION

As the magnitude of resection increases, the ability to correct deformity improves, but also the risk of complication increases. Therein, an understanding of potential applications and complications is helpful.

Thoracic and thoracolumbar kyphosis in adults

STUDY DESIGN

Author experience and literature review.

OBJECTIVES

To investigate the spectrum of adult kyphosis and to discuss the various surgical and nonsurgical treatment options.

SUMMARY OF BACKGROUND DATA

Kyphosis with its various etiologies and associated pathophysiologies has been discussed in the literature for many decades. The nonsurgical treatment primarily consists of symptom reduction via physical therapy and has not changed significantly for decades. The surgical treatment, however, has changed dramatically. A decade ago, most large kyphotic deformities required anterior and posterior procedures. With the advent of numerous posterior osteotomy techniques and pedicle fixation, most of these deformities are now treated via posterior methods only.

METHODS

Using literature review and the author's experience, kyphosis and its characteristics will be discussed. Important details pertinent to presurgical planning and execution of surgical will be discussed. Three cases will be presented to illustrate the surgical treatment options for three qualitatively different kyphotic deformities.

RESULTS

Flexible kyphotic deformities may respond well to aggressive facetectomies and cantilever corrections. Multisegmental osteotomies may be most appropriate for long sweeping deformities. Fixed, sharply, angulated deformities may respond best to pedicle subtraction osteotomies or vertebral column resections.

CONCLUSION

Segmental pedicle screw fixation coupled with one of four posterior osteotomy/resection techniques can be used to address most sagittal plain deformities. Careful application of these techniques is important. Smith-Petersen and Ponte osteotomies are most appropriate for long sweeping deformities with mobile anterior columns. Pedicle subtraction osteotomies and vertebral column resections are most appropriate for fixed, sharply angulated spinal deformities. The successful application of these techniques is dependent on accurate preoperative evaluation of the structural properties of the kyphosis and meticulous execution of the surgical technique.

Predictors of clinical results of radial osteotomies for Kienböck's disease

The factors affecting the clinical results after radial osteotomies for Kienböck's disease are unknown. In the current study, we reviewed the data of 41 patients treated with radial osteotomies for Kienböck's disease and analyzed which preoperative factors significantly affected the clinical results of these procedures. Lateral closing wedge osteotomies of the radius were done for 22 patients (six patients with Lichtman Stage II disease, three patients with Lichtman Stage IIIA disease, 12 patients with Lichtman Stage IIIB disease, and one patient with Lichtman Stage IV disease) with zero or positive ulnar variance, and radial shortenings were done for 19 patients (four patients with Stage II disease, two patients with Stage IIIA disease, 12 patients with Stage IIIB disease, and one patient with Stage IV disease) with negative ulnar variance. The mean age of the patients at surgery was 36 years and the average followup was 38 months. To statistically assess the prognostic factors, multiple regression analysis focused on the postoperative clinical score as a dependent variable and preoperative patient data as independent variables. In the current analysis, patient age was the preoperative factor most clearly predictive of clinical results after radial osteotomies for Kienböck's disease. We think that the lower effectiveness of radial osteotomies must be considered in doing these procedures for elderly patients.

[Excellent results of surgical management of osteoarthritis. Arthroplasty and osteotomy provide pain relief and restore joint function]

The treatment of osteoarthrosis is through the insertion of an artificial joint, arthroplasty. Quantitatively, operations of the hip and the knee are the most important and the results are extremely well documented and good both in terms of functional results as well as in terms of longevity. In recent years, arthroplasty of other joints such as the elbow and the shoulder has been developed to a satisfactory degree of perfection. Even the ankle joint, hitherto resistant to arthroplasty, has yielded promising results. In the knee joint, osteotomy is a viable alternative.

Restricted surface matching--numerical optimization and technical evaluation

Accurate and reliable registration is one of the most important issues in computer-aided surgery, as small errors may have a large influence on the overall accuracy of the system. The restricted surface-matching algorithm (RSM), initially developed for periacetabular osteotomy surgery (PAO), has been improved to become numerically more stable and reliable. To assess the accuracy and sensitivity of registration, a framework is presented that evaluates two aspects of registration: the sensitivity and raw performance of the registration algorithm are tested in a stand-alone environment, and the integration into a CAS system is analyzed by evaluating the accuracy of the complete system. For the latter tests, spherical-headed titanium screws used as fiducial landmarks provide a reference transformation for the registration. This framework was used to analyze the performance of RSM for PAO surgery. The sensitivity analysis showed the algorithm to be insensitive to noise up to a magnitude of 3 mm. Both the sensitivity analysis and simulated surgical environment tests showed that an accuracy can be attained of better than 2 mm in the region of interest, and better than 4 mm far away from the region of interest. This is sufficient for safely assisting PAO surgeries.

Malunion in the lower limb. A nomogram to predict the effects of osteotomy

Nomograms derived from mathematical analysis indicate that the level of malunion is the most important determinant of changes in the moment arm of the knee, the plane of the ankle and alterations in limb length. Testing in five patients undergoing reconstruction showed a mean error of postoperative limb length of 2.2 mm (SD 0.8 mm), knee moment arm of 4.7 mm (SD 3.3 mm) and ankle angle of 2.6 degrees (SD 2.3 degrees). These nomograms provide the information required when assessing whether a particular degree of angulation may be accepted.

Cleft palate and craniofacial teams in the United States and Canada: a national survey of team organization and standards of care. The American Cleft Palate-Craniofacial Association (ACPA) Team Standards Committee

OBJECTIVE

This study is the first comprehensive national survey of the organization, function, and composition of cleft palate and craniofacial teams in the U.S. and Canada. Complete descriptions of cleft and craniofacial teams are not currently provided in the literature, and this study will provide an overview for health services research and policy use. Conducted by a national organization, this study examines teams in detail using a pretested and standardized methodology.

DESIGN

All known (n = 296) North American cleft palate and craniofacial teams were contacted for team listing purposes using a self-assessment method developed by an interdisciplinary committee of national stature. Team clinical leaders classified their teams into several possible categories and provided data on team care. The response rate was 83.4% (n = 247).

RESULTS

The distribution of listed teams was: 105 (42.5%) cleft palate teams, 102 (41.3%) craniofacial teams (including craniofacial teams that are both cleft palate and craniofacial teams), 12 (4.9%) geographically listed teams, and 28 (11.3%) other teams (including interim cleft palate teams, low-density cleft palate teams, and evaluation and treatment review cleft palate teams). Eighty-five percent of all teams systematically collected and stored clinical data on their team's patient population in the past year. Furthermore, 50% of all teams had a quality assurance program in place to measure treatment outcomes. Other findings presented include the annual number of face-to-face team meetings; new and follow-up patient censuses; and surgical rates for initial repair of cleft lip/palate, orthognathic/osteotomy procedures, and intracranial/craniofacial procedures.

CONCLUSIONS

Two of five North American teams classify themselves as having the capacity to provide both cleft palate and craniofacial care. An additional two of five teams limit their primary role to cleft palate care. Issues are raised regarding the distribution of teams, the regionalization of craniofacial services, health policy, and resource allocation.

Mechanical comparison of biplanar proximal closing wedge osteotomy with plantar plate fixation versus crescentic osteotomy with screw fixation for the correction of metatarsus primus varus

Proximal crescentic metatarsal osteotomy is a clinically successful technique for correcting metatarsus primus varus in hallux valgus surgery. However, there have been instances of dorsal elevation of the metatarsal head with this technique. Mechanical testing on 10 matched pairs of cadaver feet was performed to evaluate a new technique combining a biplanar closing wedge osteotomy and plantar plate fixation versus crescentic metatarsal osteotomy. The specimens were tested in cantilever-bending mode on an MTS Mini Bionix test frame. The mean load-to-failure values were 127.2 +/- 81.9 N (SD) for biplanar osteotomy with plate fixation and 44.9 +/- 43.3 N for crescentic osteotomy (P = 0.019); the mean stiffness values at the initial portion of the load-deflection curve were 83.11 +/- 73.76 N/mm and 31.95 +/- 43.00 N/mm, respectively (P = 0.012). The biplanar wedge osteotomy with plantar plate fixation demonstrated significantly stronger fixation than the crescentic osteotomy, with higher mean load-to-failure and stiffness values. This newly described technique may provide an acceptable alternative for patients at risk for dorsal elevation of the metatarsal, particularly those who are noncompliant or have osteopenia. Clinical study will determine whether this new technique offers satisfactory long-term results.

Resection of the radial head: an alternative to use of a prosthesis?

Prosthetic substitution of the head of the radius after comminuted fractures has not yielded satisfactory long-term results. For this reason, resection of the radial head is to be preferred in many cases. In the period from 1971 through 1985, 23 resection of the radial head were performed. After a follow-up interval of 17 years, on average, we did a personal reexamination of all patients. Using the Morrey score, we obtained 18 very good, 4 good, and 5 satisfactory results, but not a single poor outcome. On the basis of reports in the literature and our own results, we recommend resection of the radial head, especially in cases in which stable osteosynthesis cannot be achieved, as long as there are no better long-term results of prosthetic substitution of the radial head.

The chevron osteotomy: a clinical and radiographic analysis

This is a retrospective study of the chevron osteotomy for hallux valgus. Subjective and objective postoperative results were evaluated. Differences in the postoperative correction of the intermetatarsal 1-2 angle and the first metatarsophalangeal angle were noted using two accepted measurement methods. Seventeen patients (23 feet) with an average age of 39 years (range, 15-51 years) and an average follow-up of 3 years (range, 1-5 years) were studied. The average preoperative intermetatarsal 1-2 angle was 11 degrees (range, 8 degrees to 14 degrees), and the average hallux valgus angle was 23 degrees (range, 7 degrees to 39 degrees). The apparent postoperative correction differed depending on the method of measurement used. One method consistently indicated a greater amount of correction in both the intermetatarsal and metatarsophalangeal angles. The chevron procedure resulted in an overall satisfactory improvement of symptoms, function, and cosmesis. Four feet exhibited postoperative radiographic changes that could be construed as avascular changes, but there was no collapse noted, nor were there clinical symptoms of avascular necrosis. No nonunions, malunions, or infections developed, and no cases of hallux varus occurred.

The Ludloff osteotomy: a critical analysis

Fourteen Ludloff (oblique shaft) osteotomies were performed to reduce the first intermetatarsal angle on 12 female patients whose average age was 47 years. Average reduction of the first intermetatarsal angle was 6.5 degrees (postoperative average, 9.4 degrees). Average hallux abductus angle reduction was 16.7 degrees (postoperative average, 13.4 degrees). These reductions were statistically significant (P < or = 0.05). Average first metatarsal shortening was 1.4 mm. No transfer lesions nor lesser metatarsal stress fractures were noted. One patient (a 30+ pack/year smoker) sustained a delayed union. The average American Orthopedic Foot and Ankle rating score was 92.3 out of 100. Average follow-up was 48 months. This procedure is a viable alternative to closing base wedge osteotomies.

Critical steps in total knee arthroplasty. A method of analyzing operative procedures

We have analyzed the operation of knee arthroplasty using the Whiteside Mark II prosthesis, and found that it could be broken down into 42 steps, some of which are more important than others and can be considered as critical. We have identified 4 criteria to evaluate a critical step: 1) it must be necessary to complete the procedure, 2) it must take a significantly longer time to perform than other steps, 3) it must be revised significantly more frequently than other steps and 4) it must take significantly longer to revise than other steps. Two steps have been found to which all 4 criteria applied, namely placement of the femoral cutting jig and the first femoral saw cuts.

Osteochondrosis of the elbow: a review of the pathogenesis and a new approach to treatment

To test the hypothesis that joint incongruity contributes to the pathogenesis of elbow osteochondrosis, the left and right radius and ulna of 20 young large breed dogs were measured to determine any variation in length and to observe any incongruity of the elbow joint. Both lame and normal dogs were included in the study. Nine of the 20 dogs had marked disparity in radial and ulnar lengths yet only one had obvious elbow joint incongruity. The use of a sliding osteotomy for the treatment of fragmented coronoid process and a lengthening osteotomy for the treatment of an ununited anconeal process is also discussed. All four dogs treated with a sliding osteotomy showed a marked clinical improvement, and two of the three dogs treated with a lengthening osteotomy showed radiographic fusion of the anconeal process.

Precision of orthognathic surgery. A computerized cephalometric analysis of 27 patients

The precision of orthognathic surgery was evaluated in 27 patients. Rigid internal skeletal fixation was used without intermaxillary fixation. A computerized cephalometric program package (TIOPS) was utilized in the preoperative analysis, surgical planning, and postoperative examination. The mean positional difference of the cephalometric landmarks between planned and observed outcome ranged from -0.4 to 0.7 mm. Only one reference point (pm) differed statistically significantly from the plan (P = 0.02). All other mean differences in point location were of a magnitude that was not statistically different from zero (P > 0.05). It was concluded that no systematic sources of error could be demonstrated. However, the range of random variation in the individual cases left room for considerable improvement.

Surgical accuracy in orthognathic surgery

This study investigated the accuracy with which the planned surgical change could be achieved during orthognathic surgery, based upon the retrospective cephalometric analysis of 62 patients who received correction of dentofacial deformity. It is concluded that, despite individual variation, no statistically significant difference could be demonstrated between the orthognathic prediction and the surgical outcome. This supports both the use of orthognathic profile planning and the surgeon's ability to follow the plan.

Extended osteoplastic maxillotomy. A versatile new procedure for wide access to the central skull base and infratemporal fossa

Extended osteoplastic maxillotomy provides wide, direct exposure of the lateral and/or central skull base. This procedure, developed in cadavers, has been used successfully in six patients. Briefly, the maxillofacial skeleton is partially exposed via a Weber-Fergusson incision. Osteotomies in the maxilla and zygoma completely disengage the maxilla from the facial skeleton. The maxilla is mobilized on the skin and soft tissues of the ipsilateral cheek, maintaining its vascularity. Medial positioning of the anterior osteotomy through the face of the maxilla determines the extent of exposure to the nasopharynx. The lateral osteotomy can be placed anteriorly at the malar eminence or posteriorly to include the glenoid fossa, thus determining the extent of exposure to the infratemporal fossa. Concurrent use of a pterional or temporal craniotomy provides corresponding access to the cranial cavity. Miniplate fixation of the maxilla and zygoma reestablishes skeletal contour. This new, versatile procedure can be used for benign and malignant lesions of the nasopharynx and infratemporal fossa, particularly in those patients requiring preoperative or postoperative adjuvant therapy.

Rheumatoid wrists treated with synovectomy of the extensor tendons and the wrist joint combined with a Darrach procedure

Forty-three rheumatoid wrists in 43 patients with bilateral wrist involvement were treated with synovectomy of the extensor tendons and wrist joint combined with a Darrach procedure in the period from 1966 to 1986. Clinical and radiologic assessment of the wrists was carried out after an average follow-up period of 11 years, with comparison of the treated and the opposite untreated wrists. The authors confirmed what others have concluded regarding the operation: pain was generally decreased, forearm rotation increased, and wrist extension and palmar flexion changed little. Radiologically, carpal collapse and palmar carpal subluxation progressed nearly parallel to the opposite wrists, but ulnar carpal shift was much greater in the surgically treated wrists. Therefore it is suggested that some measure to prevent ulnar carpal shift, such as Clayton's tendon transfer or radiolunate arthrodesis, should be included in this operation.

Complications encountered in the treatment of pilon fractures

A total of 52 tibial plafond (pilon) fractures in 51 patients were retrospectively reviewed from the years 1985-1990 to define the rate of complications encountered during their management. All fractures were managed under faculty supervision at a level I trauma center and its two affiliated institutions. The follow-up period was scrutinized to determine whether or not a complicating event occurred. Major local complications, termed events, were defined as those requiring unplanned surgery due to infection, wound breakdown with subsequent flap coverage, and failure of fixation or fracture healing. Reduction accuracy and final clinical results were not specifically examined. There were 14 (27%) type I, 17 (33%) type II, and 21 (40%) type III Ruedi-Allgower fracture types. The majority (79%) of the fractures were closed and 89% were treated by open reduction and internal fixation. The overall local complication rate was 54%. A total of 21 (40%) pilon fractures (six type I, six type II, and nine type III) had major local complicating events requiring 77 additional operations. Patient follow-up time ranged from 1 week (the occurrence of a major local complication) to 200 weeks (no complication), with a mean of 67 weeks. Kaplan-Meier survivorship (K-M) analysis was utilized to statistically estimate the complication rate in this patient population accounting for the occurrence of censored events. The K-M-determined event rate was 42 +/- 7%. Ten (of 21) pilon fractures had events by 3 weeks, while only two occurred beyond 40 weeks.

[Resection of the proximal carpal bones in the sequelae of scaphoid fractures]

Proximal row carpectomy has precise indications in cases of severe sequelae of scaphoid fractures. This procedure may be indicated either as first-line treatment in a case of advanced pseudarthrosis with osteoarthritis, particularly radio-scaphoid, or secondarily after scaphoid pseudarthrosis has been unsuccessfully treated by other methods. It is essential to make sure that the head of the capitatum and the radial surface of the lunate bone have a satisfactory appearance on plain X-rays, MRI and occasionally arthroscopy. The overall results of this operation which retains wrist movements and which also preserves a good grip strength are very encouraging, as demonstrated by the series of 48 cases of sequelae of scAphoid fractures treated by this technique.

[Emergency resection of the proximal carpal bones]

Nine cases of emergency proximal row carpectomy are analysed. In 3 cases, the resection was performed in the context of transcarpal amputation in which the bone shortening obtained by resection allowed revascularisation without a flap. The functional result was poor because of the severity of the initial lesion. In the other 6 cases, consisting of proximal row bone defects or so-called intreatable fracture-dislocations, the results in terms of pain, range of movement and strength were similar to those obtained with elective operations.

[Operative technique of arthroplastic resection of the three proximal bones]

Proximal row carpectomy is a controversial operative technique for difficult wrist problems. Based upon resection of bones, it represents in fact a reconstructive technique of a new joint. The majors steps of the technique are described in detail.

[Multicentric study of 143 cases of resection of the proximal carpal bones]

Proximal row carpectomy is an old procedure but the good results published in the literature, it still has bad reputation. The authors conducted a retrospective multicentric study in 143 patients, 128 of whom were post-traumatic cases. And results were good in terms of pain relief. Increase in grip strength was observed in 80% of cases. Wrist range of motion was not improved by resection. The results were not predicted by preoperative status. No prognostic factor could be defined on the basis of study.

[Experimental proximal carpectomy. Biodynamics]

Proximal carpectomy was performed in 10 fresh cadavre wrists. Dynamic x-rays were taken and the forces necessary to obtain different movements before and after the operation were measured. Comparison of these parameters clearly defines the advantages and limitations of carpectomy and indicates the reasons.

[Resection of the proximal carpal bones versus partial arthrodesis in carpal instability]

Ten resections of the proximal row of carpal bones and 42 partial arthrodese were performed for carpal instability. Whenever possible, the authors prefer the second operation. This choice is often made during the operation and essentially depends on the presence of radio-scaphoid osteoarthritis and the condition of the cartilage of the head of the capitatum.

[Wrist arthrodesis: alternative to resection of the proximal carpal bones?]

The results of a series of 36 post-traumatic radio-carpal arthrodeses were compared with those of the series of resection of the first row of carpal bones reported during the round table. The advantages and disadvantages of both procedures were discussed. Arthrodesis results in: 1) loss of grip strength in all cases, averaging 41%; 2) persistent pain in 78% of cases; 3) impairment of function resulting from blocking of the wrist. After the procedure, average time off work is 15 months, level of permanent disability was 30%, and 20% of patients returned to their previous jobs. These figures could be used as arguments against arthrodesis. However, they must be taken in context: final arthrodesis, usually performed on manual workers, is often chosen when resection of the first row of carpal bones would obviously be insufficient, for example, when severe arthritis of the head of the capitate is present.

[Biomechanic considerations in wrist prostheses]

At the present time, in disorders of the wrist, avulsion of the first carpal row is the most commonly used technique as a last resort. However, there are many wrist prostheses, which are reviewed here. Roughly, they belong to two families: the three axis prostheses (spherical) that cannot transmit to the hand the pronation supination torque, because of their geometrical characteristics, and the two axis prostheses (universal joint) that are able to transmit this movement. The characteristics of future prostheses must include: based on the "universal joint" principle, occupy minimum space, isometric, maintain tendon tension, an axis identical to the true axis of the wrist, to maintain the hand in line with the forearm, fixed without cement but, not shortened with time, possibilities of mechanical flexibility immediately and lastingly stable, to be easily replaced modularly. This ideal prosthesis will certainly exist one day and will take the place of the first carpal row avulsion. In the meantime, this technique will still have a long use.

Tricorrectional bunionectomy for surgical repair of juvenile hallux valgus

The authors propose the use of the tricorrectional bunionectomy as an alternate correction of severe deformity in juvenile hallux valgus. In the past, hallux valgus surgery in juveniles has been avoided. A follow-up study of the tricorrectional bunionectomy as the surgical treatment for juvenile bunion deformity in seven patients is presented.

["Congenital" dislocation of the radial head. A bilateral case developing around the age of ten]

Dislocation of the head of the radius has important repercussions on pronation-supination, elbow stability and on the wrist joint. In the absence of a history of trauma, this anomaly is generally considered to be "congenital". Few authors have described the progressive acquisition of this dislocation during growth. The case of a 20 year old man is presented, corresponding to initial subluxation which gradually evolved towards dislocation of the head of the radius at about the age of 11 years. This type of dislocation appears to be related to abnormal growth of the proximal radial epiphysis, responsible for repercussions on the humero-radial articular relations and on the anatomy of the upper extremity of the radius. The patient was treated by ulnar osteotomy at the age of 17 years according to Hirayama's technique, when he was probably already too old. Surgical correction of the subluxation of the head of the radius at an earlier age would probably have been preferable.

Current concepts in the use of bone grafts in facial fractures. Basic science considerations

In choosing the ideal donor site for bone replacement, attention must be given to the recipient site's revascularization potential and mechanical needs. Based on histologic differences in architecture as related to these two factors, the most appropriate graft type may be harvested. Future potential exists for bone replacement by distraction osteogenesis without the need for remote site harvesting. This may provide for the most identical bone replacement.

'Z' metatarsal osteotomy: modified Mitchell's osteotomy for hallux valgus

The Mitchell's osteotomy is an established and successful operation for hallux valgus. We report a previously undescribed procedure comprising a step or 'Z' osteotomy that is a simplified version of the Mitchell's osteotomy which involves less extensive soft tissue dissection and avoids opening the first metatarsophalangeal (MTP) joint. In total, 51 operations in 40 patients were reviewed with a mean follow-up of 4.7 years. The results were compared with those reported by Mitchell in his paper of 1958, using the same criteria. The mean age was 24 years and 82% of patients were women. In 88% of patients the results were rated excellent or good and there were no serious complications. These results suggest that this procedure is as successful as the Mitchell osteotomy in young patients, and it may have long-term benefits.

A review of 13-years experience of osteosarcoma

Since the inception of the authors' facility, 365 patients with osteogenic sarcoma have been treated. While other facilities were surgically treating patients with primary amputation, this facility attempted limb-salvage surgery. The majority of patients being treated with limb-salvage surgery had the resected bone replaced by a metallic endoprosthetic replacement. The emphasis on conservative surgery led to the development of growing endoprosthetic replacements with the first being used in 1975. The cumulative survival of those patients with Stage 2 osteosarcoma treated at this facility between 1977 and 1984 is 48% at five years.

IIB osteosarcoma. Current management, local control, and survival statistics--the Australian experience

Current management of osteosarcoma at the authors' institution involves intraarterial induction chemotherapy using intermittent cycles of cisplatin and doxorubicin (Adriamycin), surgical resection with limb-sparing wherever possible, and adjuvant systemic chemotherapy (high-dose methotrexate with retrieval and doxorubicin). Twenty cases treated in this way between May 1983 and May 1989 are reviewed. There were 18 Stage IIB osteosarcomas and two Stage IIB malignant fibrous histiocytomas. Chemotherapeutic effect was evaluated in the resected tumors. There was little correlation between the clinical response to the induction chemotherapy and cell necrosis present in the resected tumor mass. Wide resection margins were achieved in 17 cases, a minimal margin in two, and a contaminated margin in one. Radiotherapy was used in these three cases where resection margin was in doubt. There were two local recurrences in these three cases. Four patients have died of their disease, and there was one treatment-related death. Overall probability of survival in this group of 20 patients has been expressed by the Kaplan-Meier method as 58%.

Limb-sparing surgery in skeletally immature patients with osteosarcoma. The use of an expandable prosthesis

Limb-sparing surgery has a definite role in the treatment of osteosarcoma in children. Increased survival, however, raises problems of limb-length discrepancy and prosthetic longevity. The concept of an expandable adjustable prosthesis addresses the problem of leg-length discrepancy. The problem of prosthesis longevity will require further long-term evaluation of current designs and methods of fixation, as well as the development of a permanent prosthesis or biologic replacement. At skeletal maturity, the expandable prosthesis may either be maintained or substituted with another implant or biological alternative if warranted by the clinical situation.

Telangiectatic osteogenic sarcoma of the extremities. Results in 17 patients treated with neoadjuvant chemotherapy

Seventeen patients with telangiectatic osteogenic sarcoma (TOS) of the extremities were treated with neoadjuvant chemotherapy, according to two different protocols. Preoperatively, the patients received high-dose methotrexate (HD-MTX) and cisplatinum (CPD) (HD-MTX/CPD) and doxorubicin. CPD was delivered intraarterially, the other drugs intravenously. Limb-salvage surgery was performed in 12 instances, and five patients were treated with amputation. Postoperative chemotherapy was tailored according to the grade of chemotherapy-induced necrosis. In 13 cases (86%), the resultant grade of necrosis was greater than 90% (good responders). The mean follow-up interval was 3.5 years with a range of 18 to 78 months. Fourteen patients (82%) remained continuously disease-free, while three patients developed lung metastases. Two of these died because of uncontrolled disease, whereas the third patient is alive and disease-free after metastasectomy. No local recurrences were observed. These results are better than those observed in 215 contemporary cases of conventional osteosarcoma treated with the same protocols. This study confirms that TOS is not a uniformly lethal tumor as suggested by prior reports. By employing neoadjuvant chemotherapy, a high percentage of patients with TOS can be cured, and in most of them, a limb-sparing surgery is possible and safe.

Stage IIB osteogenic sarcoma

Two hundred seventy-one consecutive patients treated from 1976 through 1986 were reviewed to estimate long-term survival. Disease-free survival for the entire cohort was 77% at five years and 74% at ten years. Humeral lesions had the best probability of survival (84% at ten years), followed by tibial lesions (81%) and femoral lesions (67%). Histologic response to preoperative chemotherapy was the strongest predictor of outcome. Those with little response had a survival estimate of 54% at ten years as compared to 68% for partial responders and approximately 90% for complete responders. Local recurrence was seen in 6.6% and was associated with an adverse effect on survival. Only two of the 18 patients with local recurrence have been rendered long-term disease-free survivors.

The management of IIB osteosarcoma. Experience from 1976 to 1985

From 1976 to 1985, 75 IIB osteosarcomas have been treated out of a total of 98 osteosarcomas at the authors' institution. Because of the effective chemotherapy including high-dose methotrexate administered during this time period, the surgical management changed, and only ten patients out of the 75 IIB osteosarcomas required an amputation. The overall result of 76.7% of disease-free, three-year survival was equally distributed regardless of the surgical procedure. Endoprosthesis, resection with or without grafts, and rotationplasties, as well as amputations, revealed similar results. No negative influence from the limb-sparing surgery could be observed.

Intraarterial cisplatin in the management of stage IIB osteosarcoma in the pediatric and adolescent age group

Sixty patients with extremity osteosarcoma were treated with intraarterial cisplatin. This was followed by surgical resection (amputation or limb salvage) and postoperative adjuvant chemotherapy utilizing two different protocols. Seventy-five percent of patients achieved an initial response. Overall disease-free survival was 58%. The number of patients treated with limb-salvage surgery gradually increased to the extent that 80% of newly-registered patients achieved a response and were subjected to limb salvage. Disease-free survival was 48% in amputation and 68% in limb salvage. The only factors found to have prognostic significance in determining disease-free survival were extent of tumor destruction induced by preoperative chemotherapy and tumor size.

IIB osteosarcoma. Current management, local control, and survival statistics--The Netherlands

Guarded optimism is justified in light of the results of treatment of IIB osteosarcoma in the Netherlands. This is due to improvements in diagnostic imaging techniques, staging, adjuvant chemotherapy, and surgical treatment. Five-year survival rates have increased from 25% to 80%. En bloc resection is currently possible. This makes reconstructive procedure justified, both from an oncologic and orthopedic view. Many questions are still unanswered, concerning evaluation of tumor necrosis because of chemotherapy, optimal adjuvant therapy, functional evaluation of different types of reconstruction, and psychological development of the patient. An international gathering of data on the overall treatment of IIB osteosarcoma is advocated to find answers on the above-mentioned questions. A noninvasive adjustable-lengthening prosthesis is mentioned as a Dutch solution to leg-length discrepancy. This prosthesis can be used after limb-saving surgery in young children.

Congenital hip dislocation or dysplasia with subluxation: a radiologic study

We studied the behavior of hips in congenital hip dislocation. Two types were identified: those that developed normally after closed reduction and those that required an osteotomy. Children with hips that required an osteotomy were older at presentation and at follow-up had worse subluxation, with shallower acetabula. In this group, the younger the age at which reduction was achieved, the less the residual subluxation of the hip at follow-up. The age at which the late osteotomy was performed did not appear to affect the residual hip subluxation or the acetabular development. We could not find any radiologic parameter that would predict the need for an osteotomy.

Impact of two cycles of preoperative chemotherapy with intraarterial cisplatin and intravenous doxorubicin on the choice of surgical procedure for high-grade bone sarcomas of the extremities

The authors assessed the impact of two cycles of preoperative chemotherapy (POCT) with intraarterial cisplatin (120 mg/m2) and continuous intravenous doxorubicin hydrochloride (Adriamycin; 20 mg/m2/day x 3 days) on the decision to perform a limb-sparing procedure (LSP) or amputation in 22 patients with high-grade bone sarcomas of the extremities. The tumor types were osteosarcoma (17), malignant fibrous histiocytoma (three), leiomyosarcoma (one), and malignant schwannoma (one). Surgical stages were IIA (three), IIB (17), and IIIB (two). The prechemotherapy surgical options chosen were 12 amputations (55% of patients) and ten LSPs (45%). The initial decisions to amputate were based on a combination of the following: improper biopsy (five cases), large tumors (ten) and those with neurovascular encroachment (six), and pathological fracture (one). Following chemotherapy, 18 LSPs (81%) and four amputations (19%) were performed. Nine of 12 patients (75%) initially deemed unresectable were converted to LSP. The median tumor response (necrosis; range, 0%-100%) was 70%; ten of 22 specimens had necrosis greater than 95%. Median tumor necrosis for the patients treated by amputation and LSPs was 45% and 88%, respectively. Following surgery, all patients received four additional cycles of cisplatin and doxorubicin. The median follow-up period is 30 months; six patients have developed metastatic disease, with a median disease-free interval of 16.6 months. The rate of local tumor control is 95% (21 of 22 patients).(ABSTRACT TRUNCATED AT 250 WORDS)