Secondary Thumb Reconstruction via Ectopic Banking of Bony Phalanges From a Nonreplantable Amputated Thumb: A Follow-Up Study.

PURPOSE: This study aimed to evaluate the radiological and functional results of secondary thumb reconstruction via ectopic banking of bony phalanges from a nonreplantable amputated thumb. METHODS: Thumb reconstruction was performed using the bony phalanges from a nonreplantable amputated thumb that were ectopically banked in a subcutaneous pocket. A wraparound flap was harvested from the ipsilateral great toe and wrapped around the bone graft. After surgery, the results were assessed in terms of infection, range of motion, bone union of the graft, and signs of osseous resorption of the reconstructed thumb. RESULTS: Fifteen patients underwent secondary thumb reconstruction using this technique between January 2003 and October 2018. Ten patients were followed up for at least 6 months (6 months to 9 years) and were included in this study. All wraparound flap transfers were viable. No bone graft infection was observed. In the 6 cases in whom the interphalangeal joint was not fused, the interphalangeal joint motion ranged from 5° to 60° with an average of 35.0° ± 15.1°. The metacarpophalangeal joint motion ranged from 5° to 66°, with an average range of motion of 48.2° ± 23.6° for the cases in whom the joint was not fused. In 8 of the 10 patients, the time of bone ectopic banking was within 10 days. In these patients, bone union with no osseous atrophy was observed. In 2 patients whose phalanx was banked for more than a month, different degrees of bone resorption of the grafted phalanx were evident after transplantation, although no further treatment was required. CONCLUSIONS: Bony phalanges from a nonreplantable amputated thumb can be ectopically banked and used for secondary reconstruction of the thumb. The duration of banking before thumb reconstruction should be no more than 2 weeks. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.

Resorption of Iliac Bone Grafts Following Wrap-Around Flap for Thumb Reconstruction: A Follow-Up Study.

PURPOSE: To study the bone resorption pattern of iliac crest grafts after thumb reconstruction with a wrap-around flap from the hallux. METHODS: Patients who underwent thumb reconstruction with a wrap-around flap from the hallux were followed up. We measured the length, proximal, middle, and distal widths, and proximal, middle, and distal thicknesses of the iliac crest grafts on posteroanterior and lateral radiographs and used the length, width, and thickness ratios of the iliac grafts and the first metacarpal bones to calculate the amount of bone resorption. Data from 2 groups reconstructed with or without a terminal tuft were analyzed. RESULTS: Fifteen patients were followed for an average of 20 months (range, 14-72 months). Bone resorption occurred in all 3 measured dimensions in all patients and the degree of resorption increased with time. Resorption amounts of the length dimension in the group with a terminal tuft was significantly decreased compared with those in the group without a terminal tuft at 6 months, 12 months, and the last follow-up. The resorption amount of the width dimension of the distal portion was significantly less in the group with a terminal tuft at the last follow-up. The resorption amount of the thickness dimension of the distal portion was significantly lower in the group with a terminal tuft at 12 months and at the last follow-up. CONCLUSIONS: Bone resorption occurred in all dimensions of the graft after thumb reconstruction using a wrap-around flap from the hallux. Flaps including the terminal tuft had less bone resorption in the distal portion. Wrap-around toe flaps should only be used in cases of thumb amputations at the middle of the proximal phalanx and distal, and the terminal tuft should be preserved in the flap; fixation with a plate should be avoided. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.

Preservation of Devitalized Bone in Necrotic Digits Following Crush Injury With Free Tissue Transfer.

Traditional management of necrotic digits has been to allow demarcation between viable and nonviable tissues to occur, and thus to indicate the level of amputation required. In this case report, the phalangeal length of the necrotic thumb was maintained in 2 patients who had sustained crush injury. After nonviable soft tissues were debrided, the devitalized bones were covered with soft tissue flaps. All wounds healed without infection. Both cosmetic and functional results of the reconstructed thumbs were satisfactory. In one patient, radiographs of the thumb demonstrated resorption of the distal phalanx, but this did not impede daily use. This experience supports an earlier observation suggesting that devitalized bone can be covered for salvage in some cases.

[Elution properties of linezolid bone cement].

OBJECTIVE: To explore the elution properties of linezolid bone cement so as to guide the clinical application of linezolid bone cement in the treatment of infection after total joint arthroplasty. METHODS: The specimens of bone cement (40 g each) were divided into 6 groups depending on mixed different contents with linezolid (5 specimens in each group), group I (1.2 g), group II (2.4 g), group III (3.6 g), group IV (4.8 g), group V (6.0 g) and group VI (7.2 g). The time-dependent elution of linezolid from bone cement was measured by high performance liquid chromatography (HPLC). RESULTS: The release rate of linezolid bone cement samples was positively correlated with the concentration of antibiotics. And he release rate increased with the rising concentrations. The release of all groups dropped dramatically at Day 1. And as of Day 2 there was a slow release at a very low level. The elution of all groups persisted through 7 weeks. The analysis of variance between groups showed significant differences in release rates. And further examination by q test revealed that the release of group of 3.6-7.2 g was significantly higher than other groups. CONCLUSION: The drainage tube should be clamped at Day 1 post-operation so that there is a full release of high concentration of linezolid. Adding 3.6 g linezolid to 40 g cement may provide better cost-effective outcomes.

[Analyses of microbiology and antibiotic susceptibility in prosthetic knee infections].

OBJECTIVE: To explore the microbiological etiology of prosthetic knee infections during two-staged revision and analyze antibiotic susceptibility of bacteria so as to provide clinical recommendations for empiric antibiotic therapy. METHODS: A retrospective review was performed for 78 hospitalized patients for prothetic knee infections undergoing two-staged revision between January 1, 2007 and February 28, 2014.Suspicious intra-operative tissues were collected and cultured. Microbiological data sets and antibiotic susceptibility of bacteria were analyzed. RESULTS: Micro-organisms were isolated from 65 patients. The negative culture rate was 16.7%. The most common genus encountered was Gram-positive isolates (75.7%), followed by Gram-negative isolates (20.5%) and fungi isolates (2.7%). Polymicrobialinfections accounted for 15.4% of patients. The most common causative organism of infection was coagulase-negative staphylococci (46.6%) and followed by Staphylococcus aureus (20.5%). The detection rate of methicillin-resistant staphylococcus(MRS) was 34.3% (25/73) and it accounted for 47.5% of staphylococcus.Gram-negative isolates were dominated by Escherichia coli (4/15) and Acinetobacter baumannii (4/15). All A.baumanniiscame from polymicrobial infection. Coagulase-negative staphylococci and A. baumannii were the most common causative organisms of polymicrobial infection. The results of antibiotic susceptibility showed cefazolin and cefuroxime were poorly susceptible to isolates. The drug resistance rates were 43.5% and 53.6%.Some third or fourth generation cephalosporins also have problems of bacterial resistance.Some antibiotics such as vancomycin, linezolid, imipenem, rifampin, cefoperazone/sulbactam and levofloxacin had high rates of drug sensitivity. CONCLUSION: Most infections are caused by staphylococci. The proportion of isolated MRS is high.Empiric prophylacticantibiotics therapy may include vancomycin and cefoperazone/sulbactam to cover Gram-positive and Gram-negative organisms.Empiric therapeutic antibiotics therapy includes vancomycin and carbapenems. After the results of antibiotic susceptibility, antibiotics should be timely adjusted.

Injectable Magnetic Hydrogel Filler for Synergistic Bone Tumor Hyperthermia Chemotherapy.

The therapeutic efficacy of bone tumor treatment is primarily limited by inadequate tumor resection, resulting in recurrence and metastasis, as well as the deep location of tumors. Herein, an injectable doxorubicin (DOX)-loaded magnetic alginate hydrogel (DOX@MAH) was developed to evaluate the efficacy of an alternating magnetic field (AMF)-responsive, chemothermal synergistic therapy for multimodality treatment of bone tumors. The prepared hydrogel exhibits a superior drug-loading capacity and a continuous DOX release. This multifunctionality can be attributed to the combined use of DOX for chemotherapy and iron oxide nanoparticle-containing alginate hydrogels as magnetic hyperthermia agents to generate hyperthermia for tumor elimination without the limit on penetration depth. Moreover, the hydrogel can be formed when in contact with the calcium ions, which are abundant in bone tissues; therefore, this hydrogel could perfectly fit the bone defects caused by the surgical removal of the bone tumor tissue, and the hydrogel could tightly attach the surgical margin of the bone to realize a high efficacy residual tumor tissue elimination treated by chemothermal synergistic therapy. The hydrogel demonstrates excellent hyperthermia performance, as evidenced by in vitro cytotoxicity tests on tumor cells. These tests reveal that the combined therapy based on DOX@MAH under AMF significantly induces cell death compared to single magnetic hyperthermia or chemotherapy. In vivo antitumor effects in tumor-bearing mice demonstrate that DOX@MAH injection at the tumor site effectively inhibits tumor growth and leads to tumor necrosis. This work not only establishes an effective DOX@MAH system as a synergistic chemothermal therapy platform for treating bone tumors but also sheds light on the application of alginate to combine calcium ions of the bone to treat bone defect diseases.

Multi-needle blow-spinning technique for fabricating collagen nanofibrous nerve guidance conduit with scalable productivity and high performance.

Nerve guidance conduits (NGCs) have been widely accepted as a promising strategy for peripheral nerve regeneration. Fabricating ideal NGCs with good biocompatibility, biodegradability, permeability, appropriate mechanical properties (space maintenance, suturing performance, etc.), and oriented topographic cues is still current research focus. From the perspective of translation, the technique stability and scalability are also an important consideration for industrial production. Recently, blow-spinning technique shows great potentials in nanofibrous scaffolds fabrication, possessing high quality, high fiber production rates, low cost, ease of maintenance, and high reliability. In this study, we proposed for the first time the preparation of a novel NGC via blow-spinning technique to obtain optimized performances and high productivity. A new collagen nanofibrous neuro-tube with the bilayered design was developed, incorporating inner oriented and outer random topographical cues. The bilayer structure enhances the mechanical properties of the conduit in dry and wet, displaying good radial support and suturing performance. The porous nature of the blow-spun collagen membrane enables good nutrient delivery and metabolism. The in vitro and in vivo evaluations indicated the bilayer-structure conduit could promoted Schwann cells growth, neurotrophic factors secretion, and axonal regeneration and motor functional recovery in rat.

Technical note: Intraoperative ultrasound measurement for evaluating the stability of the inferior tibiofibular joint in patients with ankle fractures.

OBJECTIVES: Injury to the tibiofibular syndesmosis is a common complication of ankle fractures. Currently, it is challenging to determine the stability of the tibiofibular joint caused by ankle fractures during surgery. This study aims to establish a standardized method for dynamically evaluating the stability of the inferior tibiofibular joint under intraoperative ultrasound and assess its utility in surgery, thereby assisting in determining the necessity for fixation of the inferior tibiofibular joint after fracture reduction and fixation. METHODS: The stability of the inferior tibiofibular joint was assessed using an intraoperative ultrasonic external rotation stress test, with a torque set at 7.2 N·m. The measured parameters included the width of the inferior tibiofibular space in neutral (N) and external rotation (E) positions, stretch ratio (E/N), and injured/healthy side stretch ratio (I/H). Patients with Weber B or C type ankle fractures were selected as participants. RESULTS: For the case with Weber C fracture, the N measurement was 4.22 mm after fracture fixation, while E measured 5.77 mm and E/N ratio was 1.37, which were larger than those on the healthy side (N: 4.17, E: 4.50, E/N:1.08), with an I/H ratio of 1.27. Intraoperative X-ray revealed instability of the inferior tibiofibular joint. After inserting a tibiofibular screw, the N measurement was 4.20 mm, while the E measurement recorded 4.32 mm, resulting in an E/N ratio of 1.03 and an I/H ratio of 0.95, indicating improved joint stability. For the Weber B fracture case, the N measurement was 3.55 mm after fracture fixation, while E measured 3.98 mm and the E/N ratio was 1.12, slightly lower than those on the healthy side (N: 3.94, E: 4.47, E/N: 1.13), with an I/H ratio of 0.99. The intraoperative X-ray revealed stability of the inferior tibiofibular joint. Therefore, no further fixation was performed on it. CONCLUSION: Standardized intraoperative ultrasound stress test allows for real-time, dynamic assessment of the stability of the inferior tibiofibular joint after ankle fracture reduction and fixation, which can help guide the fixation of the inferior tibiofibular joint, thereby reducing the risk of postoperative traumatic arthritis.

Construction of a mineralized collagen nerve conduit for peripheral nerve injury repair.

A new nerve guidance conduits (NGCs) named MC@Col containing Type I collagen (Col) and mineralized collagen (MC) was developed, enhancing mechanical and degradation behavior. The physicochemical properties, the mechanical properties and in vitro degradation behavior were all evaluated. The adhesion and proliferation of Schwann cells (SCs) were observed. In the in vivo experiment, MC@Col NGC and other conduits including Col, chitosan (CST) and polycaprolactone (PCL) conduit were implanted to repair a 10-mm-long Sprague-Dawley rat's sciatic nerve defect. Histological analyses, morphological analyses, electrophysiological analyses and further gait analyses were all evaluated after implantation in 12 weeks. The strength and degradation performance of the MC@Col NGC were improved by the addition of MC in comparison with pure Col NGC. In vitro cytocompatibility evaluation revealed that the SCs had good viability, attachment and proliferation in the MC@Col. In in vivo results, the regenerative outcomes of MC@Col NGC were close to those by an autologous nerve graft in some respects, but superior to those by Col, CST and PCL conduits. The MC@Col NGC exhibited good mechanical performance as well as biocompatibility to bridge nerve gap and guide nerve regeneration, thus showing great promising potential as a new type of conduit in clinical applications.

Contralateral C7 nerve root transfer to neurotize the upper trunk via a modified prespinal route in repair of brachial plexus avulsion injury.

PURPOSE: In this report, we present our experience on the repair of brachial plexus root avulsion injuries with the use of contralateral C7 nerve root transfers with nerve grafting through a modified prespinal route. METHODS: The outcomes of the contralateral C7 nerve root transfer to neurotize the upper trunk and C5/C6 nerve roots of the total or near total brachial plexus nerve root avulsion injury in a series of 41 patients were evaluated. The contralateral C7 nerve root that was dissected to the distal end of the divisions, along with the sural nerve graft, were placed underneath the anterior scalene and longus colli muscles, and then passed through the retro-esophageal space to neurotize the recipient nerve. The mean length of the dissected contralateral C7 nerve root was 6.5 ± 0.7 cm, and the mean length of sural nerve graft was 6.8 ± 1.9 cm. The suprascapular nerve was neurotized additionally by the phrenic nerve or the terminal motor branch of accessory nerve in some patients. RESULTS: The mean length of the follow-up was 47.2 ± 14.5 months. The muscle strength was graded M4 or M3 for the biceps muscle in 85.4% of patients, for the deltoid muscle in 82.9% of patients, and for the upper parts of pectoral major in 92.7% of patients. The functional recovery of shoulder abduction in the patients with the additional suprascapular nerve neurotization was remarkably improved. CONCLUSIONS: The modified prespinal route could significantly reduced the length of nerve graft in the contralateral C7 nerve root transfer to the injured upper trunk in brachial plexus root avulsion injury, and it may improve the functional outcomes, which deserves further investigations.

Donor foot morbidity following modified wraparound flap for thumb reconstruction: a follow-up of 69 cases.

PURPOSE: To evaluate donor foot morbidity after thumb reconstruction using a modified wraparound flap. METHODS: We observed patients who accepted thumb reconstruction with the modified wraparound flap between January 2001 and December 2009. We examined and evaluated the reconstructed thumb and donor foot. Donor morbidity was assessed on both a subjective and an objective basis using the Foot Function Index-verbal rating scales (FFI-5pt), the American Orthopaedic Foot and Ankle Society for Hallux Metatarsophalangeal-Interphalangeal (MTP-IP) scale, and gait analysis and dynamic pedodynographic measurements. RESULTS: We reviewed 69 patients; the follow-up period ranged from 6 months to 5 years, with an average of 26 months. The reconstructed thumbs had good aesthetic appearance, and static 2-point discrimination averaged 9.4 ± 2.7 mm. Full length or most of the length of the donor toes was preserved in 67 patients. The retained plantar strip was significantly enlarged from an average of 14.5 ± 1.4 mm measured at surgery to 27.8 ± 4.7 mm measured at last follow-up (p < .05), and its 2-point discrimination was 9.1 ± 2.3 mm. A total of 34 patients were available for FFI-5pt and Hallux MTP-IP scale evaluation. The FFI-5pt total score was 3.1 ± 2.7 and the total Hallux MTP-IP score was 87.9 ± 7.1. Gait analysis and dynamic pedodynographic measurements were available in 20 patients. All 5 biomechanical parameters (timing, trajectory, symmetry, average peak force, and peak pressure between donor foot and the contralateral foot) had no significant difference. CONCLUSIONS: The function of the donor foot after a modified wraparound flap for thumb reconstruction was well preserved, the degree of pain and disability in the donor foot was mild, and foot function in gait was not disturbed. Although a certain degree of restriction in interphalangeal joint motion occurred, this was nearly negligible and did not deter return to normal daily living activity, work, and recreation.

Typical brachial neuritis (Parsonage-Turner syndrome) with hourglass-like constrictions in the affected nerves.

PURPOSE: To report on 5 patients who had acute brachial neuritis (Parsonage-Turner syndrome) with hourglass-like constriction in the affected nerves. METHODS: We retrospectively reviewed 5 patients who were treated in our department from December 2003 to December 2008. Acute, intense pain around the shoulder girdle and upper arm was the first symptom and was followed by muscle weakness and atrophy. Clinical and EMG examinations showed involvement of 2 or more nerves in the affected extremity. Those severely affected nerves that had no response to conservative treatment were explored, and an hourglass-like constriction was identified. Neurolysis was performed at the sites of constrictions in 2 radial nerves and 1 median nerve. The constricted portion was resected, and direct coaptation was performed in 1 radial nerve and 1 musculocutaneous nerve. The constricted portion was resected, and nerve graft was performed in 2 radial nerves and 1 median nerve. RESULTS: All patients were followed up for 24 to 84 months after surgery. Of 3 nerves treated with external neurolysis, all attained full recovery. Of 2 nerves treated with resection and neurorrhaphy, 1 attained full recovery, and the other had an incomplete recovery. Of 3 nerves treated with resection and nerve graft, 1 (4-cm nerve graft) attained full recovery, and 2 (4-cm and 13-cm nerve graft, respectively) had incomplete recovery. CONCLUSIONS: The site of nerve lesion of brachial neuritis was not necessarily within the brachial plexus. Our finding of hourglass-like constrictions in individual peripheral nerves suggest that multifocal involvement of terminal branch lesions may underlie the complex patterns of paralysis often encountered clinically. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Risk Factors for Patellar Clunk or Crepitation after Primary Total Knee Arthroplasty: A Systematic Review and Meta-analysis.

Patellar clunk and crepitation (PCC) have been reported as a consequence of primary total knee arthroplasty (TKA). The incidence and contributing factors have not been fully defined. We performed this systematic review to evaluate factors associated with PCC following primary TKA. We identified studies on PCC following TKA from an electronic search of articles in Medline, Embase and the Cochrane databases (dated up to May 2018). Eighteen studies altogether, including 600 cases of PCC within 8,131 TKAs, were included in the meta-analysis. Several factors including demographic, intraoperative, clinical variables, and radiographic measurements were pooled for meta-analysis. Among intraoperative and clinical variables, patients involved with patellar retention (odds ratio [OR] = 9.420; confidence interval [CI]: 5.770-13.070), lateral reticular release (OR = 2.818; CI: 1.114-7.125), and previous surgery (OR = 2.724; CI: 1.549-4.790) were more likely to having PCCs. Among radiographic measurements, increased anterior tibial offset (weighted mean difference [WMD] = 0.387; CI: 0.139-0.634), increased joint line changes (WMD = 1.325; CI: 0.595-2.055), and increased knee flexion angle (WMD = 3.592; CI: 1.811-5.374) were considered risk factors associated with PCC. Demographic factors (age, gender, body mass index [BMI], and diagnosis) and other reported radiographic measurements were not associated with PCCs. This study identified intraoperative variables (patellar retention and lateral reticular release), clinical variables (previous surgery), and radiographic measurements (increased anterior tibial offset, increased joint line changes, and increased postoperative knee flexion angle) that contribute to an increased risk for PCC. Modifiable factors (patellar retention and lateral reticular release) should be considered and addressed to limit the risk for PCC following TKA. Patients with conditions that may not be modifiable may benefit from counseling about their increased risks for PCC to limit potential dissatisfaction with their procedure.

[Retrograde muscle release method in treatment of mild to moderate ischemic muscle contracture of forearm].

OBJECTIVE: To investigate the effectiveness of retrograde muscle release in treatment of mild to moderate type ischemic muscle contracture of forearm classified by Tsuge. METHODS: Between March 2010 and September 2018, 11 patients with mild to moderate ischemic muscle contracture of forearm were treated with retrograde muscle release. There were 6 males and 5 females with an average age of 24 years (range, 16-29 years). According to Tsuge classification, 6 cases were mild type and 5 cases were moderate type. The interval between injury and operation was 9 months to 25 years, with a median of 17 years. The scar cords in the muscle of the middle one-third of the forearm was released firstly. If the standard of sufficient release was not reached, further releasing the scar cords in the muscle and the tense tendon structure in the proximal one-third of the forearm and the origins of the flexor muscles was necessary. If the standard was still not reached, the origins of the flexor muscles can be released and slid. The effectiveness was evaluated from six aspects of the range of motion of the hand and wrist, dexterity, grip strength, sensation, subjective function scores [quick-disability of the arm, shoulder, and hand questionnaire (Quick-DASH) and the patient-related wrist/hand evaluation (PRWHE)] and satisfaction. RESULTS: All the incisions healed by first intention. Eight patients were followed up 1-106 months (median, 13 months). The range of motion of the hand and wrist was significantly improved, the results were excellent in 3 cases, good in 3 cases, and fair in 2 cases, with an excellent and good rate of 75%. The patient's dexterity evaluation scored a perfect score of 12, which was close to the normal hand dexterity. At last follow-up, the grip strength on the affected side was 37.6%-95.5% of the contralateral side, with an average of 77.6%. Seven patients had normal sensation before and after operation, and the two-point discrimination of median nerve and ulnar nerve was 4-5 mm at last follow-up; 1 patient with forearm mechanical crush injury still felt numb after operation, and the two-point discrimination of median nerve and ulnar nerve was 8 mm and 7 mm, respectively. The Quick-DASH score was 0-15.9, with an average of 4.5, and the PRWHE score was 0-23.0, with an average of 6.6. All the patients were satisfied with the surgery and the effectiveness. CONCLUSION: A targeted retrograde muscle release method for mild to moderate type ischemic contracture of forearm can achieve satisfactory effectiveness.

[Biomechanical research of antegrade intramedullary fixation for the metacarpal fractures].

OBJECTIVE: To study the biomechanical characteristics of antegrade intramedullary fixation for metacarpal fractures. METHODS: From March to May 2008, both the 4th and 5th metacarpals from 25 formalin embalmed cadaver hands had three-point bending test after transverse osteotomy followed by randomly fixation with one of the following three methods: plate and screw, antegrade intramedullary K-wire, crossed K-wire. While, both the 2nd and 3rd metacarpals had torsional loading test after the same management as the 4th and 5th metacarpal had undergone. RESULTS: In the three-point bending test, both the maximum bending moment (M(max)) and bending rigidity (EI) of the antegrade intramedullary K-wire were comparable with those of the plate and screw, and were significantly larger than those of the crossed K-wire. In the torsional loading test, the antegrade intramedullary K-wire had a statistically smaller maximum torque (T(max)) than the plate and screw, and had a comparable T(max) with the crossed K-wire; while, the torsional rigidity (GJ) of the intramedullary K-wire was statistically weaker than that of both the plate and screw and the crossed wire. CONCLUSIONS: One single antegrade intramedullary K-wire can provide a satisfactory M(max) and EI for metacarpal fixation and shows relatively weak in the torsional loading test. The injured finger should be well protected to avoid torsional deformity in clinical practice.

[A method of measuring the displacement of the distal radioulnar joint on the three-dimensional CT imaging].

OBJECTIVES: To establish a clinical method for measuring the displacement of the distal radioulnar joint (DRUJ) precisely irrespective of ulnar variance, and to derive normal population translation references with palmar and dorsal stress. METHODS: Thirty-seven normal distal forearms were scanned with computed tomography using an apparatus designed by Pirela-Cruz. Each extremity was scanned in two positions: maximal ulnar palmar and dorsal stress. The digital imaging and communications in medicine (DICOM) CT images were then imported into Mimics 10.0 for three-dimensional reconstruction. On the DRUJs 3D images, choose the most prominent point of the palmar and dorsal margins of the sigmoid notch and the excavate ulna fovea as the reference points A, B and C. A perpendicular line was then drawn from the point C to a line connecting points A and B with the intersection D. Calculate the ratio of AD/AB and DB/AB. Two observers measured all the DRUJs independently and one repeated the measurements one month later to determine the interobserver and intraobserver reliability. RESULTS: The mean ratio values of palmar (AD/AB) and dorsal (DB/AB) translation were 0.39 ± 0.07 and 0.37 ± 0.07, and the normal references (x(-) ± 2 s) were from 0.25 to 0.50 and from 0.23 to 0.50, respectively. No significant differences were observed in terms of positions, genders and dominant hands. The intraclass correlation coefficient (ICC) values for interobserver and intraobserver reliability (DB/AB, AD/AB) were 0.84, 0.80, 0.93 and 0.92, respectively. CONCLUSIONS: This new method could accurately measure the displacement of DRUJs with acceptable reliability, even with ulna positive or negative variance. Instability of DRUJ may be indicated when AD/AB is less than 0.25 or BD/AB is less than 0.23.

Markerless robotic pedicle screw placement based on structured light tracking.

PURPOSE: Most existing robot systems for pedicle screw placement rely on optical markers to establish the spatial relationship between the surgical tool and the surgical path. Marker installation and registration are time-consuming, and error may also accumulate along the complicated coordinate transformation chain. Therefore, we proposed a markerless structured light-based method to simplify the surgery workflow and the coordinate transformation chain. METHODS: Firstly, a structured light camera is used to directly track both the surgical tool and the bone anatomy without using markers. Secondly, a markerless "two-direction" approach for robot-camera registration together with a feedback robot control method is developed. Lastly, a prototype system is built and examined with precision validation experiments and pedicle screw drilling experiments. RESULTS: Precision validation experiments show satisfactory positioning accuracy of the system. In drilling experiments, 42 paths were drilled on three synthesized cervical vertebrae phantoms and all the paths successfully went through the pedicles. The mean position error of the entry point was 0.28 ± 0.16 mm, and the mean angle error was 0.49 ± 0.24°, which can meet the clinical requirement. CONCLUSION: The results show the feasibility of the proposed structured light-based method for pedicle screw placement, which has a simple workflow and can achieve good accuracy without using optical markers.

[Clinical analysis of 73 cases of macrodactyly].

OBJECTIVE: To analyze the clinical characteristics of 73 cases of macrodactyly. METHODS: Review the incidence, distribution, characteristic, X-rays, pathogenesis and treatment of involved digits on the base of the clinical documents of 73 macrodactyly which were treated from 1965 to 2006. Twenty-eight cases had been followed-up. RESULTS: Unilateral involved 71 cases, bilateral involved 2 cases. In upper deformities, the most involved digit was the index finger, followed by thumb and middle finger enlargement. In lower deformities, the second toes were affected more. There were 12 cases of static macrodactyly, which were all presented at or soon after birth. Sixty-one cases were progressive macrodactyly: 39 cases presented at birth; 17 cases occurred at about 2 years old; 5 cases were found after age 2. Thirty-seven cases of progressive type presented digital deviation; 3 cases associated with syndactyly; 16 cases complicated with thenar eminence hypertrophy; 8 cases of multiple-digit involved combined with palm and forearm hyperplasia. CONCLUSIONS: Macrodactyly in hand has a preference for the median nerve territory, mainly involving index, thumb and middle finger. Pedal macrodactyly prefers medial plantar nerve territory, the second toe is the most commonly affected. The progressive macrodactyly is more common than static. It may present at birth and combine with syndactyly, digital deviation, thenar eminence hypertrophy, palm and forearm hyperplasia.

[Malignant giant cell tumor of the tendon sheaths in the hand].

OBJECTIVES: To retrospectively study on malignant giant cell tumor of tendon sheath (MGCTTS) in the hand, and to evaluate its clinical, histologic, immunohistochemical features and biologic evolution. METHODS: Between January 1991 and December 2001, 10 patients with histologically proven MGCTTS were treated. The clinical material, radiographs and hematoxylin and eosin-stained sections were reviewed. Immunohistochemical studies and nuclear suspensions for flow cytometry were done on paraffin embedded tissue. All patients were followed up. RESULTS: Three of 10 patients in which the diagnosis of MGCTTS was originally considered were excluded after the slides reviewed and immunohistochemical examination performed. In the other 7 patients, one showed malignant and aggressive nature: the lesion recurred several times and the patient eventually died with pulmonary metastases. The immunohistochemical profile of the patient was similar to that reported in benign GCTTS, and the flow cytometry DNA analysis detected aneuploidy. Six cases presented histologic features of malignancy, 4 of them undertook the immunohistochemical examination and their profiles were similar to that reported in benign GCTTS. An aneuploidy DNA pattern was detected in one case on flow cytometry evaluation, diploidy DNA pattern was detected in 3 cases, and their S-phase fraction was 4.5%, 11.6% and 2.6% respectively. All of them had a benign clinical features, they were alive and without evidence of disease from 1.5 to 7.5 years (averagely, 4.5 years) after complete surgical excision or resections with wide surgical margins. None of them had received chemotherapy or radiation therapy. CONCLUSIONS: Malignant giant cell tumor of tendon sheath is an extremely rare malignant tumor, some cases have a poor outcome, the others, despite the histologically malignant features, have a good prognosis if wide surgical excision ablates the tumor completely.

The Safety of the Thenar Portal: An Anatomical Study of the Thumb Carpometacarpal Arthroscopy.

Purpose To define the localization of the distal course of the motor branches of median nerve (MBMN) and its arborization and its quantitative relationships to the thenar portal of the carpometacarpal (CMC) joint in the hope of evaluating the safety of this portal. Method In 16 embalmed cadaveric upper extremities, the localization of the course of the MBMN and its arborization were defined. In 14 fresh-frozen cadaver upper extremities, the CMC arthroscopic portals, 1-U, 1-R, and a thenar portal, were established, after which the limbs were dissected. Measurements were taken from the portals to the superficial radial nerve, radial artery, and the MBMN. Results The distal course of the MBMN and its terminal branches were all located in the proximal third of the thenar muscles, where the thenar portal was introduced. The mean distances between vital structures and each traditional portal (1-R or 1-U) were consistent with the previously published studies. Both the superficial and the profound branches of MBMN were very close to the thenar portal, and the distance between these two main terminal branches and the thenar portal was 1.2 mm (range: 0-6.2; standard deviation [SD] = 2) and 2.2 mm (range: 0-7; SD = 2.1), respectively. Five (35.7%) of the 14 fresh-frozen specimens indicated the superficial branch lay directly over the portal. One hand (7.1%) had the profound branch crossed over the thenar portal. Four hands (28.5%) indicated both the superficial and profound branches directly overlay the thenar portal. The superficial palmar branch of the radial artery was found in six hands, and in four of them, it crossed over the thenar portal. Conclusion The distal course of the MBMN and its terminal branches were all located in the proximal third of the thenar muscles, where the thenar portal was introduced. Clinical Relevance The thenar portal could improve the view of the CMC joint of the thumb and provide better performance of procedures in this joint. We should bear in mind that the arborization of the MBMN was mostly located in the proximal third of the thenar muscle, and any operation in this area should be performed with great caution.