BIPEDAL

Robert Weinstein

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Surgeon, Author, Educator and Inventor Dr. Robert Weinstein discusses all things foot and ankle health related. From common conditions and their conservative treatments to complex reconstructive surgical challenges, every topic will be explained in plain language for all audiences.

6d ago

Osteogenesis and Bone Lengthening

The core biology and historical framework are consistent with the orthopedic literature: Codivilla described early limb-lengthening work in the early 1900s, while Ilizarov's later work established distraction osteogenesis as a reproducible clinical method and characterized the importance of distraction rate and frequency. Modern bone transport remains an important option for critical-sized defects, particularly when infection or major bone loss makes conventional grafting difficult. Growing new bone by distraction is an extremely useful tool for repairing segmental defects, lengthening congenitally short segments, or where bone loss has occurred that exceeds the size of reasonable bone grafting. This method has routine use by surgeons with special training in the method. The classic apparatus used in the procedure is the circular or ring fixation, commonly called an 'Ilizarov' device. The purpose of the device is to anchor to bones internally while controlling their stability and motion externally. Axial lengthening is the archetype for understanding the procedure. First, the device is mounted to the limb using thin tensioned wires or larger diameter pins. An osteotomy is performed at a specific location, and the procedure then stops there for a latency period. This is often a week, which corresponds perfectly with the conversion of the initial hematoma into a soft callous phase. I'd refer you back to the podcast on bone healing for more information about the cellular events occurring during this transition. Once the latency period is complete distraction begins, often at the programmed target rate of 1mm per day. In numerous studies this rate was shown to be the ideal lengthening parameter for time and distance. The rhythm however must be monitored, as premature regenerate consolidation or failure of regenerate formation can be a result of too fast or too slow a distraction. Distraction occurs until the target length is achieved. Then comes consolidation, where the bone converts from soft to hard callous and ultimately gains its structural integrity. Once consolidation is complete the apparatus is removed and unconstrained tension is applied to the limb to allow further strengthening and mineralization. It is important to remember than fixation, whether internal or external, shields the bone from some stress that is required for bone to reach its full mechanical and structural potential. Axial lengthening is easy to understand. Angular deformity correction is simply distraction around an axis. The axis of deformity correction can be mathematically plotted on radiographs to establish an apex. The fixation is then constructed to work around this apex, with the end result being conversion of a crooked limb or bone into a straight limb segment after distraction is complete. This concept can be uniplanar or multiplanar. In these more complicated deformities hexapod ring systems and computer software may be employed for developing distraction schedules that result in all three planes being corrected simultaneously. After performing hundreds of these procedures, the miracle of osteogenesis is still fascinating and rewarding each and every time. The content of this podcast is for educational and informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
Sep 6

Platelet Rich Plasma

Platelet-rich plasma has become a popular treatment in sports medicine, orthopedics, and podiatry. But what exactly is PRP, and how much evidence do we actually have that it works? In this episode, we break down the science, clinical applications, and controversies surrounding PRP. What Is PRP?PRP is a concentrated preparation of a patient's own blood containing a higher concentration of platelets than normal blood. Platelets do more than help form blood clots. They contain numerous signaling proteins and growth factors that participate in tissue repair, inflammation, angiogenesis, cellular recruitment, and tissue remodeling. How Is PRP Made?The process generally involves: Drawing the patient's bloodProcessing the blood, usually with centrifugationSeparating blood componentsConcentrating plateletsRemoving or retaining varying amounts of white blood cells and red blood cellsInjecting the resulting preparation into the target tissueImportantly, PRP is not one standardized product. Different systems can produce substantially different platelet concentrations and cellular compositions. What's Actually in PRP?Depending on the preparation, PRP can contain: PlateletsPlasmaGrowth factorsCytokinesWhite blood cellsFibrinSmall amounts of red blood cellsWe discuss why leukocyte-rich and leukocyte-poor PRP may behave differently and why the optimal formulation remains uncertain for many conditions. The Science Behind PRPActivated platelets release biological mediators that can influence: Fibroblast activityCollagen productionAngiogenesisInflammatory signalingCellular migrationExtracellular matrix remodelingTissue repairBut biological plausibility doesn't necessarily equal clinical effectiveness. One of the major themes of this episode is the difference between mechanistic evidence and patient outcomes. PRP in OrthopedicsWe discuss the evidence surrounding PRP for: Knee osteoarthritis PRP has some of the more encouraging evidence in this area. Several randomized trials demonstrate improvements in pain and function, although the magnitude and durability of benefit remain debated. Rotator cuff tendinopathy Evidence is mixed, but some newer studies suggest PRP may provide greater longer-term improvement than corticosteroid injections. Tennis elbow Despite a strong biological rationale and widespread clinical use, recent placebo-controlled evidence has not demonstrated a convincing benefit over placebo. Achilles tendinopathy This is one of the most important examples discussed in the episode. Despite a compelling biological rationale, recent randomized placebo-controlled studies have failed to demonstrate a meaningful advantage of PRP over placebo. PRP in Foot & Ankle MedicineWe examine potential applications for: Plantar fasciopathyAchilles tendinopathyPeroneal tendinopathyPosterior tibial tendon disordersSelected ligament injuriesOsteoarthritisSelected postoperative or surgical applicationsThe evidence varies considerably between conditions. PRP for Plantar FasciopathySome studies suggest PRP may provide longer-term improvement compared with corticosteroid injections. However, comparisons against corticosteroid don't answer the same question as comparisons against placebo. The key question remains: Does PRP itself provide a clinically meaningful benefit beyond the effects of the injection and rehabilitation? PRP for Achilles TendinopathyDespite being one of the most popular applications for PRP, high-quality placebo-controlled evidence has been disappointing. Recent meta-analyses have found no significant improvement in pain or function compared with placebo. This illustrates an important lesson: A treatment can have a highly plausible biological mechanism without producing a meaningful clinical benefit. Why Placebo-Controlled Studies MatterInjection studies are particularly susceptible to placebo effects. Patients receive: A physician consultationA procedureA needlePost-treatment instructionsOften physical therapyAnd the expectation that treatment will helpTherefore, PRP needs to be compared against an appropriate control—not simply against doing nothing. Statistical Significance vs. Clinical SignificanceA statistically significant result doesn't necessarily mean a patient feels substantially better. We discuss the concept of the minimal clinically important difference, which asks whether the magnitude of improvement is large enough for patients to actually notice and value. Why PRP Studies Often DisagreeOne of the major problems with the PRP literature is lack of standardization. Studies may differ in: Platelet concentrationLeukocyte concentrationRed blood cell contaminationActivation methodInjection volumeNumber of injectionsInjection techniqueUltrasound guidanceRehabilitation protocolsPatient populationSeverity of diseaseFollow-up durationSo when someone says, "Studies show PRP works," an important follow-up question is: Which PRP? For which condition? Compared with what? PRP vs. CorticosteroidCorticosteroids can provide relatively rapid symptom relief through their anti-inflammatory effects. PRP is intended to influence the biological environment and may have a slower onset of benefit. For some conditions, PRP appears to provide more durable improvement than corticosteroid. For others, the difference is minimal or uncertain. Neither treatment should automatically be considered "better" without considering the diagnosis and evidence. Is PRP a Stem Cell Treatment?No. PRP does not introduce stem cells into the injured tissue. It uses the patient's own platelets and the biological mediators associated with them. Does PRP Regenerate Cartilage?This claim requires caution. Laboratory and animal studies demonstrate potentially beneficial effects on cartilage biology. Some human studies demonstrate improvements in pain and function. But symptom improvement is not the same as proven regeneration of normal articular cartilage. Clinical improvement should not automatically be interpreted as cartilage regeneration. What Should Patients Ask Before Getting PRP?Before undergoing PRP, consider asking: What is my exact diagnosis?What does the evidence show for PRP specifically for this condition?What type of PRP are you using?What is the platelet concentration?Is it leukocyte-rich or leukocyte-poor?How many injections will I need?Will ultrasound be used?What rehabilitation will accompany the injection?What improvement should I realistically expect?What are my alternatives?What will it cost, and is it covered by insurance?The Bottom LinePRP represents an exciting area of orthopedic and regenerative medicine. There is legitimate science behind the concept. There are biologically active molecules within platelets that can influence tissue healing. But the clinical evidence is far more nuanced than many advertisements suggest. For some conditions, PRP appears beneficial. For others, the benefit is modest or uncertain. And for certain conditions—including Achilles tendinopathy and tennis elbow—recent placebo-controlled evidence does not demonstrate a meaningful advantage over placebo. The most important lesson is that PRP should be viewed as a treatment option—not a cure-all. The right question isn't: "Does PRP work?" The better question is: "Does PRP work for my specific condition, using this particular preparation and treatment protocol, and is the expected benefit worth the cost and alternatives?" That is the conversation patients should be having with their physicians. The content of this podcast is for educational and informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
Aug 22

Arthroscopic Foot and Ankle Surgery

Arthroscopy involves using small scopes placed into a joint to evaluate or treat intraarticular conditions. The ankle, subtalar, and first metatarsophalangeal joints are commonly explored using this technique. Needle arthroscopy has presented a newer modality for even smaller joints in the foot. Classically, exploration of a joint in this manner was for evaluating tissues that we can't normally seen any other way. Cartilage condition is not able to be determined externally by any method, until severe degeneration occurs and the underlying bone shows changes. Small loose bodies (sometimes called a 'joint mouse') can also be missed in imaging if the slices on MRI are imperfect or the object is hiding in the recesses of the joint. OLT's or OCD's are a very common indication for arthroscopic evaluation, and if small enough management as well. Probes can be used to test the integrity of the cartilage, curettes and shavers can be used to remove loose cartilage, and abraders can be used to stimulate bleeding from the underlying bone to promote fibrocartilage formation. Impingement especially anteriorly is also a common condition where arthroscopic treatment can be beneficial. Post sprain impingement (sometimes called 'Bassets impingement') where a part of the synovium or anterior talofibular ligament folds into the joint with certain movement is particularly amenable to treatment using a scope. The corresponding synovitis, inflammation of the inner lining of the joint, can also be removed with this method. Occasionally arthroscopy is only part of a larger procedure. For example, some ankle fracture patterns would benefit from intraarticular assessment in addition to open reduction and fixation (ORIF.) Any occult damage can be visualized and either documented or repaired as required. These injuries can be missed in "routine" ORIF depending on injury pattern. Arthroscopic assisted fusion is becoming more common in certain settings. When no deformity exists requiring angular correction, using scope portals to introduce aggressive abraders that can effectively remove all of the cartilage and subchondral bone plate can be very enticing. This minimizes soft tissue disruption and potential vascular embarrassment, and can achieve the goal of adequate joint preparation for fixation. Because this technique is not nearly as common compared to open fusion methods it is unknown if fusion rates exceed or are less than traditional methods. Patients must understand - using a scope does not necessarily mean this is minor surgery ore recovery will be faster. The surgery is what it is, regardless of how we visualize or the tools we use to fix the pathology. For example, just because a fusion is performed arthroscopically doesn't make the bones unite any faster. Recovery is based on the procedure performed, not the tools used to perform the procedure. The content of this podcast is for educational and informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
Aug 15

Surgery for the Rigid Flatfoot

This episode is designed for anyone interested in foot and ankle health, including patients considering flatfoot surgery, athletes dealing with progressive deformity, medical students, residents, podiatrists, orthopedic surgeons, and anyone interested in understanding how complex reconstructive foot surgery actually works. The rigid flatfoot is not simply an arch that has fallen. It is a three-dimensional structural deformity involving the bones, joints, tendons, and ligaments of the entire foot and ankle. The goal of reconstruction isn't simply to make the arch look better. It is to create a plantigrade, stable, well-aligned, functional, and substantially less painful foot. Arthrodesis is a cornerstone of reconstructing the rigid or grossly unstable flatfoot. This involves fusion or permanent stiffening of one or more joints to achieve stability and reduce pain and dysfunction. In the case of severe adaptation or arthritis this approach has the highest likelihood of long term success. Isolated talonavicular or subtalar joint fusion are often performed, in conjunction with gastrocnemius lengthening or corrective osteotomies. However this would be entertained in earlier presentations of a painful non-reducible flatfoot. In later stages, a double or triple arthrodesis is commonly chosen for its predictability in restoring all of the major deformity components and long term stability. Often, the surgeon is tasked with developing a treatment plan based on clinical and radiographic evidence. This approach - a single recipe for a set of circumstances - is in my opinion archaic. Modern reconstruction should not follow a recipe, rather careful assessment of the condition and patient expectations and choosing the least destructive procedures to get there. A well trained foot and ankle surgeon should be nimble enough to make decisions after careful inventory both pre- and intra-operatively. And if the deformity magnitude is extreme, staging may be appropriate. Oftentimes a single procedure can be effective. For example, with profound peri-talar subluxation without adjacent joint arthritis an isolated talonavicular joint arthrodesis may be all that is required. This procedure will realign the TN joint to restore stability, reduce forefoot abduction, and effectively stabilize the calcaneus underneath the leg by way of retrograde stiffening. I have performed calcaneocuboid distraction arthrodesis in isolation for the same purpose when this joint alone is degenerated. Swinging the forefoot around on the talar head and stabilizing the lateral column from further luxation can be achieved this way, while preserving subtalar motion required for traversing uneven terrains. I have also planned for isolated joint fusion and ended up fusing multiple joints and rerouting tendons and ligaments in the end. No two flatfeet are alike, so they cannot be approached that way. The most important principle of all: Don't reconstruct the flatfoot from a recipe. Reconstruct the deformity. The content of this podcast is for educational and informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
Aug 7

Surgery for the High Arch - Pes Cavus

Pes cavus (high arch) is notoriously difficult to approach since there are so many manifestations. It may be masked since there are a variety of ways the foot and leg will compensate, and often the presenting symptoms seemingly have nothing to do with the deformity. A classic example is the chronic ankle sprainer. While the injury is in the ankle, the set up for the injury is rigidity in the foot structure. Another example is multiple hammered toes. The patient sees their curled toes, but the reason is mechanical instability across a structurally high arch leading to imbalance and downstream contractures. Notably, many of these patients suffer from neurological issues, which may not have even been discovered yet. Part of the workup for pes cavus is a thorough neurological inventory - reflexes, range of motion, muscle strength, gait observation, and occasionally EMG/NCV studies or even back MRI. The practitioner has to keep all options open for reconstruction. The goal is a stable, plantigrade foot. Lowering the arch height may be the visual objective, but restoring balance and stability is the surgical objective. This is why so much time is placed in clinical and radiographic evaluation - to formulate the best treatment plan, which is often multi-dimensional. Tendon transfers are commonly performed as part of a comprehensive surgical reconstruction. This involves changing lever arm directions and power. Assisting weaker muscles or weakening over powering muscles is the goal. When we think about the foot moving about the ankle, the lever arm and power of the tendon becomes important - tendons attaching further from the axis exert greater torque about that axis, and tendons of greater diameter exert more force than tendons of smaller diameter. Therefore it is a careful balance of force enhancement and force reduction along with force vectors that is very much an art on the part of the surgeon. Bone work is done to create a stable platform across which the tendons can function. When a structural deformity exists (for example a rigidly plantarflexed first ray) then tendon transfer alone will not achieve the goal of stability. This is when osteotomy or arthrodesis is used. In cases of neurological deficit we almost always choose arthrodesis, for its predictable long term success and maintaining a sufficient structure upon which to balance and ambulate. At least for as long as possible, and some of the neurological conditions are progressive and degenerative. The content of this podcast is for educational and informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
Jul 31

Total Ankle Replacement

End stage of arthritis in the distal lower extremity has almost always dictated fusion of a joint. Until relatively recently this was the case in the ankle. However, due to its essential role in normal gait, surgeons have long sought ways to replace rather than fuse this joint. Replacement joints have existed for decades. Early versions were fraught with complications and required revision and conversion to fusion very often. Like many procedures, refinement in design of the implant, instrumentation, and patient selection has resulted in newer versions that have fairly decent and predictable durability. The ideal patient has lower functional demands, although physically active. Adequate bone stock, a lower BMI, and adherence to strict post operative protocols round out the characteristics for a patient who will likely benefit. Morbid obesity, uncontrolled systemic comorbidities, peripheral vascular disease, neuropathy, and patients who cannot follow through with strict rehab protocols will likely have less than optimal outcomes, often requiring revision or conversion early on in their recovery. The decision to replace rather than fuse is highly individualized. Regardless of patient health, they must understand that the likelihood of some further intervention is high. This is due to the wear characteristics of the polyethylene component and high load going through the relatively small ankle joint surface area. Despite this, maintenance of sagittal plane motion becomes a deciding factor along with age, adjacent joint health, and overall desire for a more normal gait (not entirely 'normal') for a longer period of time. The content of this podcast is for educational and informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
Jul 24

Hammertoe Surgery

Boradly speaking, there are three types of digital contractures or hammertoes: Flexor Stabilization: This is the most common mechanism, often driven by overpronation (flat feet). As the foot flattens, it unlocks the midfoot, causing the flexor tendons (the muscles underneath the foot) to fire earlier and longer to stabilize the foot. These overactive flexors overpower the smaller stabilizing muscles, forcing the toe to buckle downward at the proximal interphalangeal (PIP) joint. Extensor Substitution: Common in individuals with high arches (pes cavus), this mechanism occurs when the extensor muscles (top of the foot) overpower the lumbricals and interossei muscles. The extensor tendons "bowstring" over the toe, pulling the base of the toe upward (hyperextension) at the metatarsophalangeal (MTP) joint, which in turn forces the tip of the toe downward. Flexor Substitution. This is the least common mechanism and usually results from calf muscle weakness or nerve issues. In this case, the deep flexor muscles take over to help the foot push off the ground, overpowering the stabilizing muscles and causing the toe to curl. The formation of hammertoes occurs in phases, beginning with a flexible deformity with mild muscle and tendon contracture, and often primarily a functional condition seen in weight bearing and ambulating. Later the deformities become rigid, where the affected tendons and joint capsules shorten and tighten permanently. The bones in the joint can luxate, meaning the toe cannot be straightened manually. This rigid phase leads to painful corns on the top of the toe or calluses on the ball of the foot from friction against footwear. Correction methods centers around the biomechanical cause, the rigidity of the deformity, adjacent joint stability, and likelihood of recurrence. Broadly speaking, either arthroplasty or arthrodesis is performed. For retention of flexibility arthroplasty is utilized, but for long term success more often than not arthrodesis is performed. This involves removing the articular cartilage and retention of the bone ends together through the bone healing phases. Satisfaction with these procedures approaches 90%, with the most likely complication being recurrence, especially when either arthroplasty is performed or when adjacent deformity or instability is not addressed. The content of this podcast is for educational and informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.
Jul 17

Nonunions

The "Diamond Model" (or Diamond Concept) of bone healing is a theoretical framework in orthopedic surgery and regenerative medicine that outlines five interdependent factors needed for successful fracture repair and non-union treatment: Osteogenic cells, Osteoinductive mediators, Osteoconductive scaffold, Mechanical stability, and adequate Vascularity. The first four are connected by vascularity - without blood flow no healing can occur. When evaluating a nonunion, this framework gives us a checklist upon which to determine the cause of the nonunion. A failure in any of the pillars of the model will result in a failed fusion or fracture to heal. Some conditions present specific challenges to bone healing that are not obvious. For example, obesity is widely known as a risk factor for nonunion. But it is not enough to just categorize high BMI solely; the obese individual poses challenges due to mechanical stability being inadequate, chronic inflammation where adipose tissue releases pro-inflammatory cytokines creating an environment favoring osteoclastic activity, and metabolic abnormalities such as insulin resistance and vitamin D deficiency. For me the key to a successful outcome of surgery or conservative treatment of fractures is mitigating risk factors when possible, or circumventing them altogether. However when faced with a nonunion, the surgeon has to answer the two questions - how can I improve mechanics around the nonunion site and how can I improve the tissue/organ/whole body biology? Without answering these the nonunion will likely persist leading to even further morbidity. The content of this podcast is for educational and informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

Surgeon, Author, Educator and Inventor Dr. Robert Weinstein discusses all things foot and ankle health related. From common conditions and their conservative treatments to complex reconstructive surgical challenges, every topic will be explained in plain language for all audiences.

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Robert Weinstein
Years Active

2026
Episodes

40
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Clean
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