ABSTRACT
BACKGROUND Congenital hypoplasia of the thumb type IV, also known as floating thumb, is a condition in which 2 small phalanges are attached to the hand with a thin skin bridge. Surgical management options for this condition vary from amputation to flap reconstruction. MATERIAL AND METHODS This retrospective study analyzed 11 infants with congenital hypoplasia of the thumb type IV who underwent surgical reconstruction using a modified vascularized polydactylous hallux flap. The study included 6 male and 5 female infants, aged 6 to 24 months. Functional evaluations and radiographic studies were conducted postoperatively. RESULTS All 11 patients underwent the complete surgical protocol. Successful vascular and nerve anastomoses were performed during the initial procedure, ensuring sufficient blood supply and neural connectivity to the transferred toes. The second operation showed promising outcomes, including improvements in thumb opposition, grasp strength, and overall function. Postoperative assessments demonstrated satisfactory radiographic alignment and no major complications during the follow-up period. CONCLUSIONS The modified vascularized polydactylous hallux flap reconstruction is a viable surgical option for managing congenital hypoplasia of the thumb type IV in infants. This technique effectively restores thumb opposition, grasp strength, and overall hand function, with satisfactory radiographic alignment and minimal complications. The study findings support the efficacy and safety of this surgical approach in addressing this rare congenital anomaly.
Subject(s)
Plastic Surgery Procedures , Surgical Flaps , Thumb , Humans , Thumb/abnormalities , Thumb/surgery , Thumb/diagnostic imaging , Male , Female , Retrospective Studies , Infant , Plastic Surgery Procedures/methods , Treatment Outcome , Child, Preschool , Radiography/methods , Hand Strength/physiology , Hand Deformities/surgery , Hand Deformities, Congenital/surgery , Hand Deformities, Congenital/diagnostic imagingABSTRACT
OBJECTIVE: This study aimed to introduce a minimally invasive technique in correcting residual zigzag deformities after early treatment of thumb duplication followed by fixation with a cemented frame. METHODS: Nineteen patients (14 males, 5 females; mean age, 12 years; age range, 8-14 years) with residual zigzag thumb deformities were treated with the minimally invasive technique from 2017 to 2019. The function and cosmesis of the thumbs were assessed using the Japanese Society for Surgery of the Hand. RESULTS: The mean period between the first and the second operations was 35 months (range, 12-84 months). There were Wassel types III (n=4), IV (n=13), and V (n=2) residual zigzag thumb deformities. Preoperatively, the mean alignment deformities of the interphalangeal and metacarpophalangeal joints were 23° (12-42°) and 18° (11-33°), respectively. The mean function and cosmesis of the thumbs were 12 points (range, 8-14 points). There were 1 fair and 18 poor scores. At the final follow-up (mean, 28 months; range, 24-33 months), the mean alignment deformities of the interphalangeal and metacarpophalangeal joints were 1° (0-4°) and 18° (0-4°), respectively. The mean function and cosmesis of the thumbs were 18 points (range, 16-20 points). There were 5 excellent results, 13 good results, and 1 fair result. CONCLUSION: Residual zigzag thumb deformities can be successfully corrected with the minimally invasive technique, resulting in good functional and cosmetic outcomes. The technique can be used as an alternative in selected cases. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.
Subject(s)
Hand Deformities , Polydactyly , Male , Female , Humans , Child , Adolescent , Thumb/surgery , Polydactyly/surgery , Hand Deformities/surgery , HandABSTRACT
BACKGROUND: Surgical outcomes of duplicated thumbs differ depending on the branching type. The authors developed a new classification system and report surgical outcomes with an average 10.2-year follow-up. METHODS: A total of 529 patients with 562 duplicated thumbs were reviewed. Surgical anatomies were compared with radiographs, and then a new classification system was developed based on branching level and bone shape observed on the radiograph: distal type (D-type), including Wassel types I and II; proximal type (P-type), including Wassel types â ¢ and â £, and four subdivisions (Po, Pa, Pb, and Pc) according to bone structure; and metacarpal type (MC-type), including Wassel types V and VI. All hands were assessed using the Japanese Society for Surgery of the Hand evaluation form, and factors causing poor outcomes were analyzed. RESULTS: There were 25% D-type, 59% P-type, and 14% MC-type hands; 2% of hands were not classified. Overall, 351 hands (63%) were directly assessed when patients reached 5 years of age. Seventeen percent of hands had fair results. Good results were achieved in 90% of D- and Po-type hands. Pa-, Pb-, Pc-, and MC-type hands had lower Japanese Society for Surgery of the Hand scores than did D- or Po-type hands. Pa- and Pb-type hands tended to develop interphalangeal joint malalignment and instability, whereas Pc- and MC-type hands developed disorders in the metacarpophalangeal joint with growth. CONCLUSIONS: The authors' new classification system clarifies the potential pitfalls for each type of duplicated thumb. More than 90% of D- and Po-type hands obtained good results. Care should be taken with interphalangeal joint reconstruction for Pa- and Pb-type hands. Meticulous reconstruction of the metacarpophalangeal joint is essential for Pc- and MC-type hands. This analysis provides important information for surgeons and patients. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, IV.
Subject(s)
Hand Deformities , Plastic Surgery Procedures , Polydactyly , Humans , Thumb/surgery , Polydactyly/surgery , Lead , Hand Deformities/surgery , Treatment OutcomeABSTRACT
BACKGROUND: Historically, amputation and pollicization has been the recommended surgical treatment for Blauth type III hypoplastic thumbs. However, due to aesthetic objections or cultural preferences, some parents seek out alternative surgical options. The present study describes a nontraditional technique that preserves and augments the hypoplastic thumb. METHODS: Patient charts were retrospectively reviewed to identify patients with Blauth type III hypoplastic thumbs who underwent thumb reconstruction at our institution from 2008 to 2018. The reconstruction procedure involved toe phalanx transfer, staged tendon transfers, and lengthening as needed. Motion was assessed categorically as ability to flex, extend, or oppose the thumb. Functionality was assessed as ability to pinch and grasp with the surgical hand. Patient- or parent-reported improvement in thumb function was also recorded. RESULTS: Of the 13 patients, 100% could flex, extend, and oppose the thumb to some degree. Eleven patients (85%) had functional one-handed grasp, and 9 (69%) had a functional pinch. Eleven patients (85%) reported no functional limitations of the operative hand. Thirteen patients (100%) reported improvement in hand function after surgery as compared to pre-operatively. There were 2 minor complications (15%), both of which resolved after intervention. No patients experienced donor-site morbidity. CONCLUSIONS: Reconstruction of Blauth III thumbs is a nontraditional technique that allows for digit retention by salvaging the hypoplastic thumb. In the present study, the majority of patients had functional thumbs and all reported postoperative improvement. Overall, our results suggest that reconstruction is a viable surgical option for Blauth III hypoplastic thumbs.
Subject(s)
Hand Deformities , Plastic Surgery Procedures , Humans , Thumb/surgery , Thumb/abnormalities , Retrospective Studies , Hand Deformities/surgeryABSTRACT
Pollicization has been a very successful procedure in the treatment of specific types of hypoplastic thumb. Although much has remained the same since early descriptions of the procedure in the 1800s and 1900s, refinements over the years have made it safer and more predictable. Over the years at our institution we have studied, modified and refined our incisions to produce a new thumb that is aesthetically pleasing with excellent function. We present our technique for pollicization along with pearls and pitfalls we have discovered.
Subject(s)
Hand Deformities , Orthopedics , Child , Humans , Hand Deformities/surgery , Thumb/surgery , Fingers/surgeryABSTRACT
Objective: To investigate the effectiveness of soft tissue balance technique by flexor pollicis longus (FPL) tendon transfer for Wassel â £-D thumb duplication in children. Methods: A clinical data of 14 children with Wassel â £-D thumb duplication met the selection criteria between January 2017 and January 2021 was retrospectively analyzed. There were 5 boys and 9 girls with an average age of 21.6 months (range, 18-35 months). Ten cases were left hand deformity and 4 cases were right hand deformity. During operation, the radial thumb was excised, and the FPL tendon of the radial thumb was used to reconstruct the soft tissue balance of the ulnar thumb. Postoperative evaluation included the range of motion (ROM) of passive flexion and extension of the interphalangeal joint (IP) and metacarpophalangeal joint (MCP), the alignments of the IP and MCP, the percentage of the width of the nail plate and the circumference of the thumb at the level of the IP to contralateral thumb. Results: All operations were completed successfully, and all incisions healed by first intention. The children were followed up 12-36 months (mean, 21.7 months). At last follow-up, the ROM of passive flexion and the deviation of the IP, and the deviation of the MCP significantly improved when compared with those before operation (P<0.05); the ROM of passive extension of the IP and the ROM of passive flexion of the MCP did not significantly improve when compared with those before operation (P>0.05). The ROMs of passive extension of the MCP were 0° before and after operation. The width of the nail plate was 76.6%±4.1% of the unaffected side, and the circumference of the thumb at the level of the IP was 92.0%±9.1% of the unaffected side. Conclusion: The soft tissue balance technique by FPL tendon trasfer can effectively correct the alignment of the Wassel â £-D thumb duplication in children, and maintain the correction effect effectively, but further follow-up and comprehensive evaluation are needed to investigate the long-term effectiveness.
Subject(s)
Hand Deformities , Thumb , Child , Female , Hand Deformities/surgery , Humans , Infant , Male , Retrospective Studies , Tendon Transfer/methods , Tendons/surgery , Thumb/surgeryABSTRACT
BACKGROUND: Deformities of the hands occur in most patients with recessive dystrophic epidermolysis bullosa. All structures of the hand may be involved. To restore hand function, it is necessary to identify the proper method of treatment. PATIENTS AND METHODS: We conducted a retrospective review of 18 patients for a total of 30 surgically treated hands. The data were collected between 1998 and 2016 at Hôpital Necker Enfants Malades (Paris, France) and Institut de la Main (Paris, France). The postoperative follow-up period ranged between 22 months and 168 months, with an average duration of 76 months. The procedure performed on all of these patients involved a first web release for the thumb and pseudosyndactyly release for the remaining digits. A full thickness skin graft was used at the level of the first commissure and palm of the hand, while acellular dermal substitutes (Integra® or Matriderm®) were used to cover the remaining commissures, digits, and the remainder of the hand, followed by a split thickness skin graft. Postoperative rehabilitation ensued. RESULTS: Long-term results are encouraging, demonstrating maintenance of function greater than 3 years in 57% of cases, and greater than 5 years in 33% of cases. CONCLUSION: We believe that good surgical technique followed by good rehabilitation, combined with an interdisciplinary overall management of these patients, allowed us to succeed in maintaining a very satisfactory, esthetic, and functional result exceeding 5 years for one-third of patients. The resultant psychological benefit is very important.
Subject(s)
Epidermolysis Bullosa Dystrophica , Hand Deformities , Epidermolysis Bullosa Dystrophica/surgery , Hand/surgery , Hand Deformities/surgery , Humans , Skin Transplantation/methods , Thumb/surgeryABSTRACT
The aim of this study was to assess the clinical results after extensor indicis proprius opponensplasty in patients with carpal tunnel syndrome and severe thenar muscle atrophy. Forty patients who underwent this procedure during open carpal tunnel releases. The mean follow-up period was 17 months (range 10 to 36). Kapandji scores significantly improved from 5.5 before surgery to 9.6 at final follow-up. Thumb pronation angle also significantly improved from 111° before surgery to 149°. Side and pulp pinch strength significantly improved postoperatively, as well as DASH scores at final follow-up. In conclusion, the extensor indicis proprius tendon transfer technique represents a reliable opponensplasty procedure to achieve consistent results in patients with severe carpal tunnel syndrome.Level of evidence: IV.
Subject(s)
Carpal Tunnel Syndrome , Hand Deformities , Carpal Tunnel Syndrome/surgery , Hand Deformities/surgery , Humans , Muscular Atrophy/surgery , Tendon Transfer/methods , Tendons/surgery , Thumb/surgeryABSTRACT
This retrospective study analyses long-term outcomes of reconstruction for congenital thumb hypoplasia Grades 2 and 3 A. In 22 thumbs (mean follow-up 9 years), instability of the metacarpophalangeal joint was found in 20 thumbs regardless of the method of reconstruction, double breasting of local tissue with or without adductor pollicis advancement or use of a slip of flexor digitorum superficialis to supplement local tissue. There was a trend towards a greater global strength, higher Kapandji score and better subjective function score when the abductor digiti minimi was used as an opposition transfer as compared with the flexor digitorum superficialis. Results for motion and subjective parameters were consistent with comparable studies though these comparisons are compromised by different methods of classification and assessment. Consistent application of an expanded Blauth grading system and a formal hypoplastic thumb score will improve the ability to compare pre- and postoperative status, different techniques and results from different centres.Level of evidence: IV.
Subject(s)
Hand Deformities , Thumb , Hand Deformities/surgery , Humans , Metacarpophalangeal Joint/surgery , Muscle, Skeletal , Retrospective Studies , Thumb/abnormalitiesABSTRACT
BACKGROUND: Pollicization of the index finger can be considered the gold standard technique for the treatment of congenital thumb aplasia. The aim of this study was to review the described incisions for pollicization and to create an anatomical framework enabling the study and comparison of these incisions. METHODS: A systematic review was performed to collect descriptions of incision sets. An anatomical model was created from the two upper limbs of the same cadaver. Thumb aplasia was modeled on both hands of this cadaver by severing the thumbs; an index finger pollicization was performed on one of the two hands. Comparative analysis of scar positions, first web size, and neothumb aspect of each incision set was conducted using a surgical glove modeling the skin. The glove was fitted onto the aplastic model to draw the incisions and then onto the pollicized hand to adjust the resulting flaps after cutting. RESULTS: Twelve articles, two textbooks, and one DVD were included in the review, either containing an original description of incisions, or describing an incision pattern with figures and references to the initial author. A total of five different incision sets, described by Buck-Gramcko, Blauth, Foucher, Ezaki, and Malek, were identified and compared using the anatomical model. CONCLUSIONS: This work summarizes five original incisions described for index pollicization in thumb aplasia and presents a standardized and reliable model to study and compare these different sets. The model can be used for educational purposes, either to teach or to optimize an incision set.
Subject(s)
Fingers/transplantation , Hand Deformities, Congenital/surgery , Hand Deformities/surgery , Models, Anatomic , Plastic Surgery Procedures/methods , Thumb/abnormalities , Equipment Design , Fingers/abnormalities , Humans , Plastic Surgery Procedures/education , Surgical Flaps/transplantation , Thumb/surgeryABSTRACT
We present the MRI findings for 39 Wassel Type IV duplicated thumbs in 38 patients. We found that MRI revealed the morphology of the cartilaginous connection between the thumb anlages and the location of the deviation corresponding to the classification of Horii, which allowed precise preoperative planning of corrective osteotomies. All 39 thumbs were available for follow-up after surgical reconstruction at a mean of 29 months (range 25 to 39). Four out of nine Horii Type A cases and all 12 Type B, as well as the six Type C and the six Type D cases, achieved good results according to the Tada scoring system. Five Type A cases achieved fair results with residual stiffness of the interphalangeal joint. No secondary operations were needed. We conclude that MRI proved useful in subclassifying Wassel Type IV duplicated thumbs and may aid in planning the osteotomies needed for their reconstruction.Level of evidence: IV.
Subject(s)
Hand Deformities , Plastic Surgery Procedures , Polydactyly , Hand Deformities/surgery , Humans , Magnetic Resonance Imaging , Osteotomy , Polydactyly/surgery , Thumb/diagnostic imaging , Thumb/surgeryABSTRACT
BACKGROUND: Surgical correction of ulnar drift of metacarpo-phalangeal joint (MPJ) due to Rheumatoid arthritis (RA) is conventionally done by silicon joint arthroplasty which is expensive and may be associated with many complications. We report the outcome of low-cost autologous interpositional arthroplasty. MATERIAL AND METHODS: Five patients (8 hands, 32 arthroplasties) underwent correction of ulnar drift of MPJ by dorsal capsule interpositional arthroplasty. Results were assessed according to the degree of recovery of movement at the MPJ and correction of ulnar drift. Functional improvement was graded as excellent, good and fair. Pain alleviation was assessed by visual analogue score (VAS) score. RESULTS: Excellent results were seen in 3 patients (5 hands, 20 arthroplasties), good in 1 patient (2 hands, 8 arthroplasties) and fair in 1 patient (1 hand, 4 arthroplasties). VAS score for pain decreased from mean preoperative 8.2/10 to 1/10. On average follow up of 1.4 years there was good hand function, no recurrence of deformities and patients were pain free. CONCLUSION: Interpositional arthroplasty for MPJ using dorsal capsule for correction of post RA ulnar drift is a low-cost option which improves the hand function and cosmesis. Additionally, it avoids all the complications related with the use of silicon joints.
Subject(s)
Arthritis, Rheumatoid/complications , Arthroplasty, Replacement/methods , Hand Deformities/surgery , Metacarpophalangeal Joint/surgery , Adult , Arthroplasty, Replacement/economics , Female , Hand Deformities/economics , Hand Deformities/etiology , Humans , Male , Middle Aged , Retrospective Studies , Treatment Outcome , Young AdultABSTRACT
The traditional management of Manske 3B and 4 thumbs is index finger pollicization. Recently, the transfer of composite tissues from the foot to reconstruct the thumb or the carpometacarpal joint has allowed the preservation of a five-digit hand. Concerns remained about the donor site and also the limited functional and cosmetic outcomes that could be achieved. This article challenges the existing dogma in the management of hypoplastic thumbs, that pollicization should always be the reference standard. We describe the evolution of techniques with free vascularized metatarsal transfer, our refinements and our proposal for a new classification system that accommodates these modifications. With increased experience, acceptable outcomes that are comparable with pollicization can be achieved.
Subject(s)
Carpometacarpal Joints , Hand Deformities , Fingers , Hand Deformities/diagnostic imaging , Hand Deformities/surgery , Humans , Thumb/diagnostic imaging , Thumb/surgeryABSTRACT
PURPOSE: The purpose of this study was to evaluate surgical outcomes of thumb preservation surgery for Blauth type IIIB hypoplastic thumbs using a nonvascularized toe phalanx to reconstruct the carpometacarpal joint. METHODS: We reviewed the records of 12 patients with Blauth type IIIB thumb hypoplasia who underwent nonvascularized toe proximal phalanx transfer from the fourth toe. Stability and mobility of the thumb, lateral pinch power, and the percentage of the thumb length relative to the index finger proximal phalanx were evaluated. Outcomes were also assessed with the Functional Dexterity Test, a visual analog scale for daily use of the operated thumb, and for overall functional and appearance satisfaction of the parents. RESULTS: Age at operation ranged from 0.9 to 11 years (mean, 3.0 years; median, 1.5 years). The mean follow-up period was 7.6 years (minimum, 3 years). Secondary reconstruction was planned in all 12 patients, but 2 families did not desire a second surgery. Secondary reconstruction consisted of tendon transfer for opposition, adduction, and/or extension of the reconstructed thumb and/or realignment surgery of the thumb axis by arthrodesis or corrective osteotomy. Eleven patients had good carpometacarpal joint stability. Thumb opposition was possible to the little finger in 7, to the middle finger in 3, and not possible in 2 patients. The mean lateral pinch strength was 18% of the contralateral normal side. The relative length of the thumb was 57% of the index finger. Time in seconds to complete Functional Dexterity Test was 83 seconds in the affected side and 38 seconds for the contralateral side. The visual analog scale suggested parental satisfaction for both the appearance and the function. The parents felt that their child used the reconstructed thumb more frequently when manipulating large objects than when manipulating small objects. CONCLUSIONS: Nonvascularized toe phalanx transfer is a useful procedure to preserve the thumb in Blauth type IIIB thumb hypoplasia. It provides a mobile, stable thumb that is functionally useful for the child and satisfying for the family. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic IV.
Subject(s)
Carpometacarpal Joints , Finger Phalanges , Hand Deformities , Child , Child, Preschool , Hand Deformities/surgery , Humans , Infant , Thumb/surgery , ToesABSTRACT
SUMMARY: Pollicization can be performed for secondary thumb reconstruction after traumatic injury or for primary thumb construction in cases of congenital thumb hypoplasia. Given the complexity of this operation, intimate familiarity with the involved anatomy and surgical principles is key to successful surgical outcomes. In this Video Plus article, the authors present a step-by-step approach to pollicization in case of Blauth type IIIB thumb hypoplasia.
Subject(s)
Fingers/transplantation , Hand Deformities/surgery , Surgical Flaps/transplantation , Thumb/abnormalities , Child , Female , Humans , Thumb/surgery , Treatment OutcomeABSTRACT
Pollicization of the index finger allows to reconstruct the hand's ability to pinch and grasp. It has been broadly used to address traumatic loss of the thumb. Today it is the procedure of choice for severe congenital thumb hypoplasia. It allows children prehension of small and large objects and gives the hand a more normal appearance. This is a demanding technique with well-defined and perfected steps that, if carefully performed, can minimize complications.
Subject(s)
Hand Deformities , Thumb , Child , Fingers/surgery , Hand , Hand Deformities/surgery , Hand Strength , Humans , Thumb/surgeryABSTRACT
We treated 16 patients with 17 hypoplastic thumbs (eight Type IIIB and nine Type IV) using a non-vascularized fourth metatarsal transfer with a rotational flap and multi-staged reconstruction. The average age at the first operation was 24 months. The average follow-up time was 46 months. All patients achieved reasonable hand function and were able to use the reconstructed thumb to grip small and large objects. The operated thumb achieved an average Kapandji score of 6.7 and average pinch strength of 0.9 kg. There were two cases of graft nonunion. All parents are satisfied with the function and appearance of the reconstructed thumb and donor foot. We conclude that non-vascularized fourth metatarsal transfer is a feasible reconstruction method for patients with Types IIIB and IV hypoplastic thumbs. The reconstruction allows for the preservation of a 5-digit hand with reasonable function and appearance and minimal donor site morbidity, although long-term growth of the metatarsals still need to be monitored.Level of evidence: IV.
Subject(s)
Hand Deformities , Metatarsal Bones , Plastic Surgery Procedures , Hand Deformities/surgery , Humans , Metatarsal Bones/surgery , Tendons , Thumb/surgeryABSTRACT
We examined the anatomical and clinical results of a new wrist subphyseal arthrodesis method called chondrodesis, which relies on resorbable suture-bone fixation for children with severe paralytic hand deformities and does not require fixation devices or bone grafting. Four children's wrists underwent the procedure, resulting in three successful wrist bone fusions. The wrists were stabilized by joint fusion in 4-5 months in good positions, ranging from neutral to extension 15°, while still allowing the forearm to keep growing since the radial growth plate remained open as of the last follow-up. The procedure improved hand function (House score, Raimondi score) and appearance. It also increased control over gripping motions with the operated hand, and even restored key pinch ability in one of the patients. The youngest patient was not able to achieve bone fusion at the key sites and will need further corrective procedures at a later and more optimal age. This novel procedure is appealing because of its technical reproducibility, low cost, encouraging outcomes, ease of rehabilitation, and because it spares the physeal cartilage.
Subject(s)
Arthrodesis/methods , Hand Deformities/surgery , Wrist Joint/surgery , Adolescent , Birth Injuries/physiopathology , Brachial Plexus Neuropathies/physiopathology , Cerebral Palsy/physiopathology , Child , Female , Hand Deformities/physiopathology , Hemiplegia/physiopathology , Humans , Male , Retrospective Studies , Wrist Joint/physiopathologyABSTRACT
The functional dexterity test (FDT) is a timed pegboard test based on the manipulation of each peg and suitable for young children as it is both simple and quick to perform. We assessed the postoperative FDT values for children with Blauth type 2 hypoplastic thumbs after opponensplasty. We evaluated hand function using FDT for 12 hands of 11 patients with Blauth type 2 hypoplastic thumbs. Opponensplasty was performed in all hands following by Huber's procedure. All patients were evaluated from 6 to 12 months after surgery for hand function using three types of FDT scores: time in seconds to complete the test (FDT time), combined total time with penalty seconds added to the initial time (FDT total), and the number of pegs per second to complete the task as a percentage against normative values (FDT speed). We compared the postoperative FDT scores with those for Blauth type 1 or 2 hypoplastic thumb patients without surgical treatment. FDT time and FDT total for the patients postoperatively were both significantly shorter than those in the type 2 patients without surgical treatment. FDT speed was significantly higher than that for the patients without surgical treatment. There were no significant differences in the three FDT scores between the postoperative patients and the type 1 patients. There were several limitations including small sample size, large ranges of the data, and high number of variables. FDT reflected postopponensplasty improvement in hand dexterity in young children with Blauth type 2 hypoplastic thumb.